4-Stroke Bike Maintenance: A Complete Guide

Over the years 4-stroke dirt bikes have improved thanks to technological advancements. There have been power increases, weight decreases, and the performance of 4-stroke engines have become a lot more efficient. Nonetheless, these types of bikes require maintenance, and while maintaining a 4-stroke isn’t as intensive as a 2-stroke, you’ll still want to make sure you know what needs to be done.

4-stroke Dirt Bike Maintenance: 

  • Wash, Dry Inspect, Tighten and lube bike (Every ride)
  • Oil change (4-6 hrs)
  • Replace Oil Filter (6-10 hrs)
  • Clean, Check, Replace, and Oil the Air Filter (Every ride or 3Hrs)
  • Replace Brake Fluid ( 20-40 hrs) 
  • Replace Pads (0.04 in-1.00mm)
  • Check Calipers and Rotors (Regularly)
  • Check Coolants (Every ride, change yearly)
  • Check Tire Pressure, Valve stems (Every ride)
  • Check Tire and wheel Condition (10k, lube every 6 months)
  • Check for Engine, Brakes, etc… for leaks (Every ride)  
  • Check Chain tension and Sprockets (Every ride) 
  • Check Control Cables (Regularly)
  • Change the Piston and Rings (Every 30-100 hours) 
  • Check Suspension/Steering (Regularly)

Make note that the maintenance of a 4-stroke dirt bike is different from that of a 2-stroke as the engines are different.

Read on to learn more about the difference between 2-stroke and 4-stroke, the importance of creating a maintenance schedule, and tips on maintaining a 4-stroke dirt bike.

How Does a 4-Stroke Engine Dirt Bike Work? 

A 4-stroke engine consists of four functions, which include exhaust, combustion, compression, and intake. This type of engine is more complex than that of a 2-stroke engine. That’s because a 4-stroke engine power is fired every two revolutions of the crankshaft, something that allows for steady power delivery.

Also, the 4-stroke engines feature a smooth powerband that makes handling easier. It’s the reason why dirt bikes with this type of engine are preferred for beginners. They require little effort to ride. The 4-stroke dirt bikes have more moving parts, and there’s controlled engine power, which means you don’t need to worry about shifting, clutching, or the brakes.

Another reason why 4-stroke dirt bikes are preferred is that they require less maintenance than 2-stroke bikes. You can comfortably use these bikes for trail riding. Nonetheless, having too many moving parts also means the bike becomes heavier than that of a 2-stroke engine. You may also need to account for the replacement of the moving parts.

4-stroke dirt bikes have more power down low. Users of the 4-stroke dirt bikes prefer them because they are easy to maneuver, control, and ride.

Differences Between 2-Stroke and 4-Stroke Dirt Bikes

Some of the major differences between the two include:

Power

Modern 4-Stroke dirt bikes have an excellent power performance due to the different advanced versions of the engines. 2-stroke dirt bikes, on the other hand, have a high power performance, but this can be difficult to control when trail riding or controlling the bike on rough terrain. The best part is that a 4-stroke bike has better power handling as power management is better than that of a 2-stroke.

Handling

Another difference between the 2-stroke and 4-stroke engine is the handling. Four-stroke engines are heavy as they have multiple moving parts. The result is challenging handling. However, two-stroke engines have fewer parts, something that makes them lighter and easier to handle. The good thing is that adding suspension can reduce handling problems in a 4-stroke dirt bike.

Operation

Another difference between the 2-stroke and 4-stroke is in the operation. A two-stroke engine has oil mixed with fuel inside. The combination goes through a combustion cycle where it burns up and leaves through the exhaust pipe. There are some 2-stroke engines with an oil injection system that adds oil into the carburetor.

2-stroke engine oil is refined as it needs to mix well with the fuel and burn in the combustion chamber. These oils are thinner and have specific additives. You can find 2-stroke engine oils made from synthetic, conventional, or castor oil.

The 4-stroke engine has a separate chamber for the fuel. There is a pump that circulates the fuel through the engine, while the filter removes unwanted particles. The process repeats, and although the oil can be recycled, it’s best to change it after some time to avoid contaminant buildup.

Four-stroke engine oil isn’t as refined due to the circulation system. Nonetheless, additives may be added. Viscosity plays a critical role in how the engines function. 

Repair

2-stroke engines have less moving parts, hence less repair and costs to rebuild. A 4-stroke engine consists of multiple moving components, which means you may have different parts to repair. That makes it costly to rebuild this type of engine.

Maintenance

Another difference between the two engines is in the maintenance. Like repair, maintaining a 2-stroke is easier because of the few moving parts. A 4-stroke bike will need more maintenance as there are a lot of parts involved. 

The Pros and Cons of 4-Stroke Dirt Bikes

Pros

  • They are fuel-efficient
  • Only gasoline required to fill up
  • Durable with proper maintenance

 Cons

  • More maintenance is required
  • Predictable power delivery
  • Can be extremely loud
  • Heavier due to the many moving parts

Change the Oil Regularly

A 4-stroke dirt bike has so many moving parts, which is why you need to change the oil regularly and lubricate these parts to ensure longevity and guarantee performance. Failure to change the oil means you may be unable to race or ride because your bike needs an engine rebuild.

How often should you change the engine oil for your 4-stroke dirt bike? The recommended time frame is five to ten hours. However, this depends on the times you race. It’s also best to buy stainless steel reusable filters as they only require cleaning using a contact cleaner when changing the oil.

When cleaning the oil filter:

  1. Spray every part with a contact cleaner to remove all the debris.
  2. Focus on the edges and the corners where dirt hides.
  3. Allow the filter to dry before putting it back inside.

You should start by reading the owner’s manual for the process of changing oil and get your model of bike. Modern 4-stroke bikes have a single oil compartment, while others have two-one for engine oil and the other for transmission. Checking the oil filler caps will tell you how many compartments your bike has.

If you are forgetful, simply write down the time you last changed the oil and remember to clean the air filters each time. That will ensure you never have to deal with engine failure.

What’s more, when dealing with a 4-stroke dirt bike, you need to change the oil filter. If you are using the stainless steel filter, you only need to clean it every time you change the oil. However, when using the disposable filter, you need to change it each time you do the oil.

What Happens to a 4-Stroke Dirt Bike Engine Without Oil?

Engine oil is what lubricates the metal parts in the engine. Lack of proper lubrication means that these parts will rub against each other at high temperatures. The result is premature wear and, finally, a damaged engine. You may need to replace most of the engine metal components, which is expensive.

How to Change Oil in a 4-Stroke Dirt Bike

Here are the steps to follow:

  1. Take the bike for a ride until the engine oil is warm. Doing this helps the used oil drain better.
  2. Put an oil pan under the bike’s bottom and remove the oil filter cap on the bike’s side. Unscrew the drain bolt on the bottom of the dirt bike. You’ll start seeing oil pouring out. At this point, shake the bike from side to side to ensure you get everything out.
  3. Remove the oil filter cover. Take the filter out and place a new filter, ensuring you cover it with some oil for a good seal.
  4. Use a contact cleaner to remove any particles and hunk on the filter cap that could block oil flow. Fit the cover in place, but avoid over-tightening the bolts. Check the rubber o-rings to see if they are loose or worn out. You’ll need to replace them if they are old and don’t fit properly.
  5. Tighten the drain bolt and add fresh oil. Use a funnel to avoid creating a mess and ensure you put the recommended amount from your user manual. Some bikes have this written on the engine casing.
  6. Clean the oil filler cap and put it tightly.

Tips on the Type of Oil to Use in a 4-Stroke Dirt Bike

The kind of oil you put depends on the bike’s brand and model. All this information is available on the user manual, but here are some tips that you should consider:

  • Don’t go for the cheapest oil in the market. Instead, opt for high-performance oil. Although it may be costly, it will keep your engine running smoothly.
  • The type of oil to choose also depends on API classification and viscosity. The thickness of the engine level is the viscosity.
  • Some engine oils are best for cold weather, while others work for warm weather.
  • Another factor to consider is the API classification.
  • Find an oil with a classification of SG or higher, apart from oils labeled as resource-conserving or energy-conserving on the label.
  • Most dirt bikes will use engine oils rated equally in performance to SJ.
  • You should stick to the name-brand dirt bike oil if you are unsure of what engine oil to get.

Be Careful About the Coolant

4-stroke dirt bikes are more involved as they have multiple moving parts. These parts can overheat and affect you on the track. Unfortunately, you can’t just add coolant and forget about it.

The 4-stroke coolant is designed to lower the engine temperature drastically and keep the engine parts from breaking down and overheating. You need to change the coolant regularly if you ride a lot or go to the sand dunes. 

Check the Tire Pressure

Another essential aspect of a 4-stroke dirt bike maintenance is tire pressure. You need to check the tire pressure in between each ride. Begin by checking the tread and any signs of visual damage like flat spots or cracks. Inspect the tires for any stuck objects in the tire like glass pieces or nails that could damage your tires.

Most riders get a range of 10,000 miles with a pair of tires. Nonetheless, this is dependent on how you ride the dirt bike and the type of bike you have. The front tires last longer than the rear ones.

It’s also critical to check the tire pressure of your dirt bike tires, especially if you are taking long rides. That helps to prevent wear and tear.

  • The best way to check tire pressure is to use a tire pressure gauge. There is an electric pressure gauge that checks the tire pressure in a minute or less. Experts recommend checking the pressure on cold tires before you ride and not after. 
  • Check the pressure of the tires often when they are new. Afterward, you can extend the pressure check intervals.
  • The recommended dirt bike tire air pressure is between 10-21 psi. You’ll need to read your user manual to know the pressure your bike needs. You can adjust tire pressure down or up to get the right traction on the terrain you’ll be racing or riding on.
  • Tires that are soft feel spongy and roll on the rim, while tires that are too hard means less grip.

All of these could affect your performance. Incorrect tire pressure could lead to uneven tire wear, tube/tire failure, punctures, and sometimes the tire may come off the bead.

Check the Valve Stem

After checking the tire pressure, you need to check the valve stem:

  • Air leaks often happen in the valve system as opposed to tire punctures or holes in the tube.
  • The valve can have dirt and debris that creates gaps in the seal.
  • When checking the valve stem, ensure the caps are on and tightened.
  • If your stem has spun, you need to deflate the tire and reset it.

Check Tire Tread, Spokes, and Rim Locks

The next step is to check the tire tread. Most traction is from the knobs that get into the terrain, instead of friction between the pavement and rubber when riding, Check between the knobs for cuts and cracks in the tire as this could affect traction.

The tire spokes and rim locks are an essential part of the tires. They need to be tight in place and straight. Find out if the rim locks are fastened.

Sometimes you may need to replace the tires. A few signs you may need to replace tires include: cracked tires, rounded knobs. discolored tires, missing or torn knobs, and tires that are more than a year old.

If it’s time to replace a tire, it’s recommended to replace both tires even if one looks better than the other. Overall, tire pressure is about experimenting. Begin with 12 psi and go down or up with the tips.

Check for Leaks

When your engine is clean, you can quickly spot oil and air leaks. You’ll notice oily drips or marks on the floor. Other signs include sooty marks on the exhaust and cylinder. Check for leaks on the brake calipers, brake fluid reservoirs, and hydraulic brake cables.

Other areas prone to leaks are coolant pipes, radiators, and the water pump gasket. In case of any leaks, ensure that you deal with them before riding the bike.

Inspect the Sprockets for Wear and Damage

The chain and sprocket are critical in any dirt bike. Unfortunately, dirt wears out the bushings and rollers. Although lubricating the chain might seem like a good idea, sometimes it could worsen the situation. The lube forms a sticky substance that attracts dirt. You need to clean the chain as this makes inspection for damage easier.

For sprockets, look for any eroded/chipped teeth and missing teeth. Worn sprockets are easy to spot. Other indicators include bent rear chain guides, bent sprockets, or chain rub blocks that are worn through. If you find them damaged, it’s best to replace both the chain and sprockets. 

Another area where people make a mistake is in the chain and sprocket alignment. That’s what leads to premature chain failure. Make sure that the chain is centered on the sprocket tooth. Use a chain adjuster to correct the misalignment. 

Ever wondered how long the chains and sprockets last? All that depends on the riding environment, maintenance, and rising habits. If you want the sprockets and chains to last longer, make sure that you inspect the drive components regularly, adjust the chain properly, and keep the drivetrain clean and lubricated. 

Check the Brakes and Brake Pads

Brake pads tend to wear out over time as the material breaks down until all that is left is the backing plate. The hardened steel can damage the brake rotor when this happens. Moreover, you could end up with brakes that no longer work. It’s critical to check your motorcycle brake pads routinely.

Brake pads that are between 0.04 in and 1.00mm need to be replaced. Some brake pads have indicator marks that are no longer visible when worn out. That is an indication to replace them immediately. Also, you need to replace other brake components like the rotors.

Carry Out Air Filter Maintenance

Your dirt bike’s air filter helps get rid of external elements you may encounter while riding. It’s essential to check the air filter regularly as dirt and debris may be embedded in the filter and not visible to the eye. Accumulation of moisture in the air filter can also result in other consequences. 

Experts recommend atleast cleaning the air filter after one ride. Ensure that the filter is also covered in a good amount of oil, as too little can easily get through the intake, and too much can weep into the engine. The air filter should be replaced between 6-10 hrs of riding depending on how hard you ride and terrain.

Exhaust Pipe Maintenance

Focus on cleaning the outside of the exhaust pipe to prevent corrosion and rust. Don’t forget to check the muffler packing. Four-stroke bikes have the muffler packing compressed, which makes it ineffective. If you notice the compression, it means that it’s time to replace it.

The best exhaust packing prevents the exhaust from becoming too hot. Some are made from fiberglass for durability and maximum performance. 

Plastic Maintenance

Your dirt bike is designed with mudguards, fenders, and side paneling to protect you and your bike from debris and dirt. They also come in handyman the event of a crash. Regular cleaning can prevent plastic parts from looking old and faded. 

When restoring the plastic parts, some experts suggest sanding the plastic as it allows for better absorption. There are plastic restorers that provide a clean and fresh look by working as an undercoat protector and a lubricant. Some block UV rays to reduce cracking and fading.

Carburetor Care and Maintenance 

Carburetors in a 4-stroke dirt bike regulate airflow through the main bore. It’s this flowing air that draws in fuel, and the mixture gets into the engine through the intake valve. They consist of a center bore, a bowl, passage, vents, jets, a slide, air/fuel ratio adjustment, accelerator pump, and idle speed adjustment.

Some of the signs that show you need a carburetor tuning include:

  • A bike that isn’t smooth to accelerate
  • Engine hiccups when the throttle is opened
  • The engine overheats even when you don’t race a lot
  • Reduced fuel efficiency

The importance of carrying out routine maintenance is to determine the right air-to-fuel ratio that the engine is getting. Adjusting these ratios ensures that your bike functions optimally. If you have a weak spark, check the ignition coil. A damaged ignition coil causes the engine to miss at high rpm and run erratically.

Clogged carburetor vent hoses are another problem that needs to be addressed. Any dirt and debris accumulation in the hoses or vent tubes causes jetting to be lean, something that makes the engine sluggish.  

A worn carburetor fuel inlet needle needs to be replaced every two years. Failure to replace it means the fuel will get into the float bowl and go up the pilot jet and into the engine. 

Spoke Tightening and Maintenance

Spoked wheels are more durable than single-piece cast wheels, and that’s the reason they are fitted on most dirt bikes. However, the spokes which are between the tire and rim are neglected. Loose spokes cab damage or break the rim, which is something that can be costly to repair or replace. Also, overtightening strips the thread and stresses the rim.

You need to check the spokes regularly by tapping them with a metallic item. A dull sound will be heard if you have loose spokes, while tight spokes have a high pitch. Check if your wheel is running true by placing it on a stand and allow it to spin freely. 

Maintaining dirt bike spokes requires tightening them when they become loose. Follow these simple tips if you’re doing this on your own:

  • You can use a spoke wrench or get a spoke torque wrench to tighten the spokes.
  • Avoid using pliers as it could damage the nipples.
  • Put the spoke wrench over the spoke’s head.
  • Turn the loose spokes anti-clockwise and examine the inside of the rim as you tighten the spoke.
  • If you need to loosen the spoke, turn the spoke clockwise. The direction is unlike regular bolts and nuts that use a clockwise direction when tightening.
  • Remove the wrench and tap on the spokes to listen to the sound.
  • If the sound is high pitched, this shows the spokes are properly tightened, but if it’s dull, you may need to tighten them again.  

Change the Piston and Rings

The durability of the piston and rings depends on how you ride the dirt bike. If you are a weekend rider, the pistons will wear out gently, but for motocross racers, the pistons wear out faster. Other factors like track conditions will affect the longevity of the pistons and rings.

It’s best to change the piston in a 4-stroke dirt bike used for racing at least every 30 hours of riding. Although most people suggest that riding a bike gently can get you up to 100 hours of a 4-stroke piston, exposing the piston to tough conditions can break it. That’s why it’s recommended to change the piston every 50 hours when riding the dirt bike gently. 

Replace Worn Out or Damaged Bearings

It can be challenging to know when bearings wear out, which is why you need to check them often and replace them once you notice something is out of place. You can check the wheel bearings by holding the dirt bike and trying to move the wheels from side to side. 

Check the swingarm linkage bearings by placing the dirt bike on its stand. Take the rear wheel and try to move it up and down. The movement will point to the top rear shock bearing or the linkage bearing. Any wheel movement shows that the bearings need to be replaced.

To replace wheel bearings, you’ll need a screwdriver, a wrench to remove the wheel, punch, hammer, bearing retainer tools, and a bearing installer/socket.  

Here are the steps to replace the bearings on a dirt bike:

  1. Start with a clean bike. Wash it to make your work easier and let you know if you have a leak or any other problem with your bike.
  2. Set the bike on a stand once it’s dry and remove the wheel that has the bearings you need to replace. 
  3. Remove the seals with a screwdriver to get to the bearings. Get rid of the retainer and flip the wheel to remove the bearing. Take the punch and push the wheel space in between the bearings to hit the bearing.
  4.  Hammer on the punch to knock the bearing out of the wheel. You want the bearing coming out straight. You’ll notice the wheel spacer out once the first wheel bearing is out. 
  5. When installing new bearings, clean the area around the wheel and set it back on the stand. Take the wheel bearing and place it on the journal. Use a piece of wood to hammer the bearing in until its flush. Install the wheel spacer once you flip the wheel over to the other side. 

Conclusion

4-stroke dirt bikes have multiple moving parts, which means they require lots of maintenance. These bikes are fast, powerful, and efficient, something that makes it ideal for trails and other races.

The above tips will help you understand how a 4-stroke bike works and how to maintain it to ensure the bike is simple to handle, easy to ride, and offers optimum power when maneuvering and controlling it. 

2 Stroke Dirt Bike Maintenance: A Complete Guide

2-stroke dirt bikes are amazing machines with a power band all their own making for a very unique riding experience. 2-strokes are said to be somewhat maintenance free but that doesn’t mean that you can just keep getting on and riding without ever giving it any love.

2-stroke dirt bike maintenance involves cleaning the air filter, checking the oil, maintaining the carburetor, cleaning and lubricating the cables, chain, and sprocket, and keeping everything clean and free of mud and dirt after every ride.

Read on to learn more about how a 2-stroke dirt bike works, signs that you may be neglecting maintenance, and some essential maintenance tips to ensure everything is working properly and you get to ride and enjoy your bike.

How Does a 2-Stroke Dirt Bike Work?

A 2-stroke dirt bike engine fires and produces power, once for each revolution of the crankshaft. Every time the piston goes up, it’s filled with a balanced combination of petrol and oil. That combination is compressed, and the spark plug ignites it, which results in an explosion. That action forces the piston to go back down, and the process repeats itself. 

What Is the Difference Between a 2-Stroke and a 4-Stroke?

The difference between these two engines is the combustion cycle process depends on the frequency the piston moves up and down during every cycle. 

For a 2-stroke engine, the whole combustion cycle requires one piston stroke to be completed. There is a compression stroke and an explosion of the compressed fuel. The return stroke means the exhaust is let out, which allows fresh fuel mixture to get into the cylinder. The spark plugs will fire every single revolution, and this produces power once every two strokes of the piston.

What’s more, you need oil to be pre-mixed in with the fuel with 2-stroke engines.

However, for a 4-stroke engine, the piston completes two strokes during each revolution. That involves one exhaust stroke and one compression stroke. They are each followed by a return stroke. The spark plugs fire once every other revolution, and this produces power every four strokes of the piston.

The 4-stroke engine does not need pre-mixing of oil and fuel as it has a separate compartment for the oil. 

Lack of proper maintenance will not only cost you in terms of the fees for replacing the parts, but it could also mean you may not enjoy your ride as much as you’d like. Below are some essential maintenance tips.

Engine Maintenance

The engine of a dirt bike plays a critical role in the overall performance of your dirt bike. The advantage of 2-stroke engines is that they don’t have valves, something that reduces their weight. They also have low output in horsepower and fire once each revolution. 2-stroke engines can function in any position as oil flow isn’t a problem. 

On the downside, 2-stroke engine parts wear out a lot. These engines also use more fuel, which means dealing with a lot of pollution. Failure to maintain the engine means you would need to replace the parts often, which is expensive. 

Signs You Need to Maintain Your Engine

Some of the signs that you may be neglecting your engine include:

  • Diminishing engine power. If you’ve noticed that engine power has diminished, this could be due to a clogged air cleaner, restricted fuel flow in the carburetor, worn rings, worn valves and seats, ignition problems, leaking gaskets, or a stuck valve. 
  • Hard to start engine. Another indication of a dirt bike engine maintenance problem is when starting your bike becomes an issue. That could be attributed to a stuck valve, worn valves, worn rings, ignition problem, leaking gaskets, the decompression system could be out of adjustment, or the cam timing could be off. 
  • Noisy top end. A loose cam chain, worn cam bearings, a worn cam chain guide, or out of spec valve clearances could all result in a noisy top end. 
  • White smoke. When a head gasket starts leaking, you may notice white smoke as soon as the engine starts burning coolant. 
  • Blue smoke. Blue smoke is an indication that the valve seals could be allowing oil to leak past them. Also, the piston rings may no longer be sealing correctly. 
  • Creamy engine oil. Creamy engine oil is an indication that moisture could be getting into the engine oil. Too much moisture in the oil should be a concern as this shows the water pump seal could be leaking.
  • Engine consumes oil. If you notice that your engine is consuming too much oil, it could be entering into the combustion chamber from worn piston rings or worn valve seals.
  • Big pieces of metal in the engine oil. Although metallic particles can be found in engine oil, large metal pieces could indicate damaged parts.
  • Engine that vibrates excessively. Worn counterbalance bearings, out of place crankshaft, a loose clutch, or a mistimed counterbalancer could cause excessive engine vibration. 
  • Noisy bottom end. Bottom end noise could be due to gears that are lubricated improperly, damaged stuck bearings, and a worn bushing and needle bearing between the clutch basket.

Tips on Engine Maintenance

Engine maintenance involves engine oil, air filters, and coolant.

Engine Oil

Dirt bike engines are small and work more with high compression ratios. 2-Stroke dirt bike engines require frequent oil changes. You should change the engine oil every ten hours of riding. It doesn’t matter the type of oil you choose as the frequency is more essential.

Pressure and heat can break down oil, and this leaves the engine vulnerable to heat buildup and performance loss. 

Changing oil on a 2-stroke dirt bike is simple. It takes a few minutes, and it’s one of the critical maintenance procedures. 

Below is a step by step guide on how to change oil.

  1. Start with a clean bike. Always start with a clean bike. You can warm up the bike as oil drains well when hot. All you need is to take the dirt bike for a spin and turn it off.
  2. Unscrew the oil cap. Place the bike upright and unscrew the oil cap on the engine casing. Ensure that no dirt drops into the transmission.
  3. Drain the oil. Put a bucket under the bike and unscrew the drain plug. That will allow the oil to drain out. You need to ensure you get rid of the oil by tilting the bike from side to side.
  4. Screw the drain plug. Once you drain out all the oil, it’s time to screw the drain plug back. Make sure that you don’t over tighten it or cross thread as this could damage the drain plug. Replace the drain plug if it gets damaged. 
  5. Put the transmission oil. Use the top filler hole to pour in the recommended amount of transmission oil. Your manual should tell you the correct amount. A few bikes allow you to check the oil levels through the check bolt on the side that you can unscrew. 
  6. Screw the oil cap. Wipe any dirt from the oil cap. Check if the washer is in proper condition to make sure it seals tightly. Screw the oil cap back, but don’t over tighten it. 

Air Filters

Air filters play a critical role in your dirt bike engine performance. A dirty air filter means airflow is affected, which means your bike won’t function as expected. What’s more, they can damage the engine by allowing dirt particles in the combustion chamber. These particles end up scratching the chamber and messing up with the piston and other parts.

The air filter could also collect moisture, and that means interfering with air filtration. That’s why it’s critical to inspect your air filter regularly. When checking your air filter pay attention to the filter oil coverage, and check for the presence of sand and silt. 

It’s recommended to clean the air filter after every ride to avoid wearing out the engine. A simple way to do this is to follow these simple steps:

  1. Get a cleaner, oil, and rim grease.
  2. Put some caps of the cleaner into warm water.
  3. Dip the dirty air filter into the warm water.
  4. Avoid turning and twisting the filter as this could damage it.
  5. Squeeze the filter and rinse it off under running water.
  6. Remove any excess water and allow it to dry.
  7. Apply oil on the filter evenly once it’s dried completely.
  8. Don’t forget to clean the rim and apply rim grease.
  9. Put the air filter back and enjoy your ride.

Coolant

Having sufficient coolant in the radiator is critical as this is what ensures the engine remains cool always. You may have changed your engine oil and cleaned out the air filter, but failure to have enough coolant could damage your engine.

Make sure you have enough coolant before each ride. If you can’t spot the level of the fluid, that means you have insufficient coolant, and you need to fill it up. When it’s too hot outside, this equals heat. Flush the radiator and put some coolant. 

Brake and Brake Pads Maintenance

Another part you should never neglect when doing maintenance is the brake and brake pads of your dirt bike. Front brake pads undergo harsh conditions and are responsible for most of the work. That’s why it’s essential to inspect the brakes and brake pads regularly to ensure you get the strongest performing braking system.

Having functional front brakes comes in handy when you are hitting the ramps since stopping distances are tight when competing. 

Front Brakes Maintenance

Start by checking the hydraulic system for adequate pressure or leaks. Simply grab the front brake lever and squeeze it to check for pressure. Inspect the front brake system from the master cylinder to the caliper, while checking for signs of dirt accumulation or wetness. 

After inspection, here are some tips on how to maintain brakes for smooth functionality:

  • Replace brake fluid. It is time to replace the brake fluid if it’s old or dirty. The fluid absorbs moisture and may require flushing. Follow the manufacturer’s recommendations when replacing the fluid.
  • Adjust the brake lever. Placing your brake lever incorrectly can lead to the constant pressure of the pads on the rotor. Also, you may be dealing with insufficient pressure. Check to ensure it is adjusted, and everything works correctly. 
  • Clean the brake pads. Clean up the brake system and the brake pads when cleaning the rest of the bike. 
  • Clean the clutch cables. The clutch cables are critical parts of your dirt bike. These cables offer access to vital controls, and that’s why you need to keep them in good condition if you plan on using your bike for a long time. You need to clean and lubricate the throttle and clutch cables after every ride. 
  • Lubricate the clutch cables. When cleaning and lubricating the cables, you need to remove the cable from the lever and perch. Disconnect the carburetor end when dealing with throttle cables and use a standard contact cleaner to do the flushing as this will clean off any grime and dirt. Also, lubricating the cables prolongs the longevity of your cables and prevents the accumulation of mud and dust. 

Chain and Sprocket Care

Another essential aspect of a 2-stroke dirt bike maintenance is the chain and sprocket care. Sprockets are critical as they help transfer power to the rear wheel through the help of a drive chain. The sprockets need to endure heavy energy loads and maintain structural functionality. 

With this regular stress, the result is constant pressure on the rear sprockets and countershaft. The parts begin to wear out. Avoid riding on dry chains and sprockets as this only damages the bike. It’s advisable to lubricate the chain and sprockets if you are looking for a smooth riding experience. 

Inspect your bike for any signs of wear and tear in the chains of your dirt bike. In case of any tear, replace the chain to avoid any accidents. Waterproof lube works best for 2-stroke dirt bike chains as it doesn’t wash away. 

Check the Transmission Fluid

Most transmission problems on a dirt bike start with the transmission fluid. The fluid resembles the engine oil as a few dirt bike models use similar oil in the transmission. Check to see if the transmission fluid is fresh and clear. 

A dark brown or black cloudy oil shows that the transmission oil is overdue for a replacement, and you need to replace it. Follow the manufacturer’s recommendations when replacing the fluid. Furthermore, you should always check the transmission fluid level a day before riding. 

Running the dirt bike with low transmission fluid could damage the internal components and lead to overheating. Low transmission fluid levels also cause wear and tear on the clutch and gears. Check the manual to know the type of oil to use and when to change the transmission fluid. 

Pipe Maintenance

The pipes are prone to corrosion and rust due to exposure to weather and road conditions. Moreover, the part between the cylinder and exhaust spigot that contains the rubber O-ring is often overlooked. 

Check the seal for cracks and other problems. It’s advisable to replace the O-ring. You can use silicone if the new ring doesn’t fit properly. 

Spoke Maintenance

Spokes often get lost, and also sometimes they can break, leading to a crash. In some cases, the spokes can get caught up in another part of the wheel. You need to check and tighten the spokes if you get a new wheel or when you have a new bike. 

When it comes to inspecting the spokes, you need to avoid going through every spoke in a row as this could make the wheel get out of true. Once you’ve tightened the first spoke, skip the next two, and check the third spoke. That means you’ll go through the spokes three times around the wheel. In case of any loose spoke, your wheel won’t be going out of true when you go around it three times.

Another thing to note is to not over tighten the loose spokes as this could get the wheel out of true. Tighten the loose spokes equally to ensure that it stays in place. A spoke torque wrench is a fantastic tool to help you tighten the spokes properly. Read the owner’s manual to understand how to tighten each spoke based on the recommended torque setting. 

Carburetor Care and Maintenance

The carburetor is the part likely to fail first if left unchecked. It keeps your dirt bike functioning at peak efficiency. Having a dirty carburetor affects performance, and this could make your bike fail to function.

Some of the signs that indicate it’s time to clean the carburetor include:

  • An engine that fails to starts
  • The engine begins to run lean when the balance of gas and fuel is thrown off
  • Presence of dirt or debris in the carburetor, causing fuel flow out
  • An engine that runs rich shows the fuel is excess, and there is insufficient air

Get the required tools before you remove the carburetor and disassemble it. You need to get: 

  • Safety gloves
  • Safety glasses
  • A service manual
  • A wrench
  • Compressed air
  • A socket wrench
  • A small screwdriver
  • A hex key
  • Rags
  • A carburetor cleaner
  • A low strength thread locker 

Start by cleaning the carburetor. However, you need to be careful. The service manual will tell you the specific tools and their size required for cleaning. 

What you need to do then is to remove the carburetor from your dirt bike. However, before that, turn off the primary fuel supply and use a tiny screw in the bike’s chamber base and a hose to drain the float chamber. Here are the next steps:

  1. Remove the slide and control cable once you’ve removed the carburetor from the engine.
  2. Turn the carburetor upside down and locate the four screws that house the float chamber.
  3. Remove the screws and use the handle of your screwdriver to loosen the chamber from the gasket.
  4. Once you remove the float chamber, you’ll see the primary jet, main floats, and jets. Remove the floats as they are delicate. 
  5. Remove the air or fuel adjusting screw in the bike’s carburetor.
  6. Check the location of the screws to determine the type your carburetor has. 

Some of the steps you should take to clean the carburetor include:

  1. Clean the float bowl. Get a carb cleaner and a rag. Use this to clean the float bowl, while checking all other components of the carburetor. 
  2. Flush out all the holes. The next step is to flush out the holes in the carburetor’s body. You can use a carburetor cleaner and compressed air to blow through these holes. Ensure that you use goggles to cover your eyes from the dirt particles and fluids that may splash from the holes.
  3. Reinstall the carburetor. The process of assembling the carburetor is similar to the disassembly process. The only thing different is that you need to check the float heights before reconnecting the float chamber. You’ll need to fine-tune the air adjusting screw every time you assemble the bike carburetor. Once you’ve reattached the carburetor and started the engine, give it time to warm up to normal temperature.

Reed Maintenance

Does your 2-stroke dirt bike always become hard to start, or do you experience carbon deposits on the exhaust opening? That could indicate an issue with your reed. Failure to check the outer corners and surfaces of the reed located within the reed cage could affect your dirt bike performance.

Monitor the reeds when you start experiencing problems with your bike. The other alternative would be to replace the reed pedals. 

Remove the screws that hold the pedal in place and install a new pedal. All you need is a screwdriver. Use a thread-locking agent on the screws to fit them in place. Moreover, use a fresh gasket when installing the reed cage back in the motor. 

Spark Plug Maintenance

The spark plug determines the running condition of your dirt bike’s engine. Cold spark plugs are used on high rpm engines, while hot plugs are used on low rpm engines. If you are having issues with fouling, you should use the stock heat range plug as a start point.

On 2-stroke dirt bikes, oil is mixed into the gasoline, something that allows the spark plug to foul out quicker than 4-stroke dirt bikes. Nonetheless, this is dependent on carb tuning. You’ll need to tune the carb on the rich side to hasten along the plug’s fouling. 

Avoid replacing the plug far outside the recommended heat range. Also, it’s best to have a spare spark plug on hand for the unexpected days. Remember that elevation affects spark plugs on 2-stroke dirt bikes because of tuning. That means it will foul faster when you overstretch your dirt bike limits. 

Another point of concern is that bad spark plugs could interfere with your dirt bike’s performance. Some signs of a bad dirt bike spark plugs include:

  • Having a flooded engine
  • A misfiring motorcycle
  • Dealing with backfiring
  • Physical indicators like rust, burn marks, corrosion, and broken tips

All of the above show that you are dealing with bad spark plugs, and you may need to replace them. 

Aging is one reason why your spark plugs could go bad. With time, the plug’s knobs on the end wear out due to sparking. A bike that detonates gas too late or too early means that all the back pressure builds up on the spark plug.

It’s recommended to replace the spark plug every five years. Fortunately, they are simple and affordable to replace. 

Plastic Maintenance

Your dirt bike comes with fenders, mudguards, and side paneling. All these plastic parts help to protect your bike from debris and dirt. These plastics also come in handy in case of a crash. The last thing you want is faded or dull-looking plastics on your bike.

It’s critical to clean the plastic regularly and keep them in top shape to prevent them from deteriorating. Sometimes you may need to get plastic repair if you break the fender or shroud while you are at the track. 

The simplest way is to stitch up the plastic by drilling some holes on both sides of the crack and running zip-ties across. You’ll need to drill a hole at the end of the crack to ensure the cf an inch apart. It’s an easy and quick way to fix the repairs while on track. 

Tire Maintenance

Dirt bike tires have an inner tube that sits inside and holds air to keep the tire attached to the rim and inflated. The tire pressure ranges from 8=18 psi, that’s because some types of terrain and riding need less or more tire pressure.

One essential thing you need to do is to check your dirt bike’s tire pressure. The best way to check for pressure is to use a pressure tire gauge. Monitor the pressure at the trail or track and not at home. If you notice that your dirt bike tire doesn’t have the right pressure, you need to use a bike tire pump to hand pump. 

Dirt Bike Maintenance Schedule

Having a dirt bike maintenance schedule is essential as it helps you keep track of areas you may have overlooked. A good maintenance schedule needs to include washing, inspection, and lubrication. It should also involve cleaning the air filter, changing the engine oil, checking tire pressure, among other things. 

Conclusion

2-stroke dirt bike maintenance is simple. All you need is to check the owner’s manual on the maintenance schedule to follow. The above tips will help you keep your dirt bike in top condition and ensure you don’t have to spend too much money replacing expensive parts.

Are Dirt Bikes Hard to Maintain?

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Dirt bikes are all about getting down and dirty and adrenaline-soaked adventures across formidable terrains. Dirt bikers will swear that no other sport can come close to motocross or trail riding. But how challenging is it to keep those dirt bikes running?

Dirt bikes require more frequent maintenance because they endure impacts and stresses more than common road bikes. To run at peak performance, they require frequent inspection and servicing. Yet most dirt bikes have more simple working parts and are easier to repair oneself than road bikes.

To understand a dirt bike’s maintenance requirements, we have created a list of common problems particular to this bike type. You may then have a clearer idea of the challenges you would expect if you decided to own a dirt bike yourself.

What Is a Dirt Bike?

Merriman-Webster defines a dirt bike as “usually lightweight motorcycle designed for operation on unpaved surfaces.” Dirt Bikes are made to be ridden on hilly and uneven terrain in all kinds of weather conditions. They are used in motocross racing popular in North America, Asia, and Europe. 

There are two larger categories within the term ‘dirt bike’ which are motocross racing and trail riding. Although the term motocross can be used for both, generally, motocross refers to the sport of dirt bike riding on a prepared outdoor track. 

Dirt Bike vs. Motocross vs. Enduro

Though every motocross bike is a dirt bike, not every dirt bike is a motocross bike. Motocross bikes are made for speed and agility and need a high degree of maintenance. Dirt bikes are less specialized and easier to maintain. Enduros are larger, heavier bikes with larger gas tanks for longer distance races.

Your average dirt bike has a long-travel suspension and rugged tires with a high seat position. These lightweights, single-cylinder bikes are designed to tackle any terrain such as desert woods or mountainous terrain.

Two-Stroke vs. Four-Stroke 

When it comes to dirt bikes, riders choose between a two-stroke (2T) and a four-stroke (4T) dirt bike motor. The 2T has one revolution of the crankshaft within one power stroke while the 4T has two. The 2T does not have a dedicated system delivering lubrication to the crankcase while the 4T does.

Common Maintenance Requirements in Dirt Bikes

Although two-stroke and four-stroke dirt bikes are easier to repair because of fewer moving parts, the maintenance necessary to maintain your bike properly is high compared to road bikes to prevent your dirt bike from malfunction or failure. 

Preventative Maintenance Requirements of a Dirt Bike

Many of the maintenance routines for a dirt bike are not excessively difficult or strenuous in themselves. These preventative maintenance requirements become a routine in a dirt bikers’ life and are part of the off-road experience.

Preventative maintenance saves dirt bike owners on costly repairs on their bikes and even prevents them from injury in extreme cases. Responsible riders follow a maintenance routine to get a longer lifespan out of their dirt bikes and overall better performance in the short term. The following is a list of what a dirt bike owner would be expected to do to maintain an optimally running dirt bike.

Wash Your Bike After Every Ride

Wash your dirt bike after each ride, whenever possible. Not only do you keep your bike’s parts free of debris and dust, but you also get a chance to look your bike over and check for any problems. A gentle wash is recommended with water and brushes or cloths. If you use a pressure hose, be extra careful to direct the water away from the bike and not into the engine or electrics. 

A great step to add to your dirt bike routine is to use your washing time to inspect your bike for problems. Preventative measures taken early can save you a lot of money in the long run with costly repairs and replacements.

Dry Your Bike Before Inspecting It

Many dirt bike enthusiasts recommend drying your bike after a wash down by taking it for a short spin. Whether you use the sun or a leaf blower to get the job done, make sure your bike is dry before conducting your maintenance inspection. Once your bike is clean and dry, you can easily spot oil drips or coolant and brake fluid leaks.

Check for Oil Leaks

Oil leaks may be a result of poor maintenance or just general wear and tear on your seals. The first culprits are usually the crankcase or a worn gasket, and a typical leak is from behind the front sprocket, which is called the countershaft seal. Wipe the oil from under your bike, visually inspect for leaks, and keep an eye out for any coolant or brake fluid.

Check your transmission oil levels and reference your user manual to determine your oil quantity and viscosity.

Inspect and Clean Your Drive Chain

If your chain is covered in mud, wait for it to dry and brush it off with a nylon brush. Once your chain is clean, lubricate it well with a high-quality chain lubricator. The lube fills in the cracks and notches where dirt can collect. 

Motocross and dirt bike riders tend to favor non-O-ring chains because they are lighter. This means they need to clean and lubricate their chains quite often, depending on the amount of riding time. It is better to lubricate your chain after your ride so that it has time to soak in and fully penetrate your chain.

Check Your Chain Tension

Your chain should always have some slack to compensate for the movement of the suspension. However, if you can remove your chain from the rear sprocket, it is too loose. The ideal amount of chain play is ½ inch (13mm) when the swingarm is parallel to the floor.

Inspect Your Bolts

Your bolts can sometimes be shaken loose under extreme vibrations and intensive riding. You should always conduct a check that your bolts are firmly in place to prevent anything shaking loose on a ride.

Check Your Bikes Controls and Control Cables

If your throttle and clutch cables show any signs of wear or fraying, you should replace them. You should also check your throttle control for the correct amount of free play. An excellent way to test this play is to:

  1. Place your bike on a work stand, start it, and let it idle.
  2. Rotate your handlebars to their full range of motion and listen carefully for any increases in your RPMs.
  3. If you hear an increase, your throttle needs more free play.

Also, check that your throttle is responsive, making sure it snaps back when twisted.

Check Your Air Filter

Your air filter plays an essential job in keeping sand, dirt, and debris from getting into your bike’s engine. A dirty air filter will affect your bike’s performance and cause damage to the piston and barrel. If you have a washable filter, you can clean your filter in warm water and a household cleaner, such as Simple Green. 

If you need to replace your filter, make sure you buy a high-quality one with a dual-stage bonded foam filter and thick sealing rings.

Check Your Tires

Your dirt bike wheel bears up quite a load, and your spokes could loosen, and your wheels may fall out of alignment. This leads to uneven weight on your hub and rim. A torque wrench is an excellent investment to ensure your spokes are the right tightness. 

Ensure your rims are round and have no dents or cracks and then check your tire pressure. It’s essential to ensure that you maintain the correct psi in your tires. You can use the TireTek Tire Pressure Gauge and ensure that your psi is correct. The average psi for all-round dirt biking is 12psi, but it can fluctuate between 8-18psi depending on the terrain.

Do an Oil Change

If you spend a lot of time in mud or your bike endures extreme duty, you should consider changing your oil more often. The frequency of oil change can depend on the particular bike, your riding conditions, and your dirt bike’s age. Your oil lubricates all the working components in your bike’s engine. 

When your oil levels fall too far, these metal components rub against each other, creating intensely high heat. This could cause your engine to seize and be permanently damaged.

Some dirt bikers advise an oil change each ride while others suggest 8-10 riding hours. Check your owner’s manual for your manufacturer’s recommendations for oil changes.

Check Your Fluid Levels

If you are racing, you should bleed your brakes every 20 hours, and recreational dirt bikers should do it every 40 riding hours. Brake fluid can go bad when it absorbs water and becomes contaminated. Off-road bikes generally use a DOT-3, 4, or 5 brake fluid, but you should check your manufacturer’s specifications in your user manual.

Grease Your Bike

Inspect your:

  • Air filter seal
  • Swingarm
  • Hardware
  • Wheel bearings and seals
  • Shock seals and forks
  • Steering head bearings

If necessary, grease these components to keep out moisture and debris and to provide lubrication. 

Check Your Brake Pads

Your brake pads may wear down over time, and if it wears down too far, it may even destroy the brake rotor. Worse yet, your brakes may fail. You need to routinely check your dirt bike brake pads and replace them at signs of thinning or visible wear. A rule of thumb is to replace the pad when 1.0mm (0.04 inches) of the brake pad remains.

Check Your Sprockets

Your sprockets transfer power to the rear wheel via the drive chain, and they endure heavy energy loads. Your countershaft and rear sprockets will wear out over time, and you should do visual checks often. A rule of thumb is to replace your sprockets when you replace your chain or every 15,000 miles. Refer to your owners manual for their particular specifications.

Other Common Dirt Bike Maintenance Requirements

Do a Compression Test

An easy way to check that your dirt bike engine condition is to perform a compression test. You may find motorcycle compression kits online, such as the OTC Motorcycle Compression Kit. The tester comes with multiple plug spark fittings and works by placing the hose and adapter into your spark plug hole. You then open the throttle and kick the bike over 5-10 times and watch for the reading at maximum pressure.

A well-functioning 250cc engine should read at about 175-200-plus psi, and a mini or 125cc should read at about 150-200 psi. If your compression is 20% lower than your baseline, you need to replace your piston and your rings.

Check Your Piston or Rings

Average intensity riders should replace their piston and rings every 20 hours on an 85/125 and every 40 hours on a 250cc. If you don’t have an hour meter on your bike, you can install an aftermarket one as its a handy way to remind yourself that it is time to perform some maintenance. Sign that your piston and rings are worn is excessive smoke and a loss of power. Pistons come in different sizes, and it’s best to use the specs to replace the piston if it has excessive wear. 

Check for Main Seal Leakage

If you notice oil residue around the seal on the bike’s magneto (left side), you can check the crank bearings for looseness to determine the leak. Main seal leaks can cause air to be drawn into the crankcase and make the bike run lean or too much air and not enough fuel.

The main seal on your transmission side will cause the oil to leak into the crankcase. The signs would be excessive smoke, the bike running rich or too much gas, and the transmission oil will smell rank. If you are uncertain, a mechanic can run a crankcase pressure test to determine the leaking seal.

Check for Other Leaks

Head gasket leaks will typically cause your motor to misfire at high rpm or when it is hot and produce white smoke that may smell of coolant. You might find leakage will occur at the top of your head gasket, and air leaks may develop at the air boot and manifold. The head gasket should be checked that it is flat and in spec. Both gasket and intake air leaks may cause erratic acceleration.

Check if Your Exhaust Valves Are Clean

Your owner’s manual should tell you how often you should clean your exhaust valves clearance. If you don’t have access to a manual, the inspection should be 15 hours to 15,000 miles. Carbon can clog your valves, and you won’t get much top end, and you will notice your spark plugs are being burned through often.

Check Your Silencer

Part of your dirt bike maintenance routine includes repacking your bike’s silencer or muffler. As a rule of thumb, you should aim to repack your muffler after every 50 hours of riding. The owner’s manual should specify your particular bike’s requirements.

Repacking is simple if you follow these simple steps:

  1. Remove the slip-on from the rest of the exhaust.
  2. Remove the outlet cap on the end of the pipe. Usually, these are screwed in, but you may need a rivet gun if it has rivets.
  3. Take out the old packing wrapped around the inner core tube.
  4. Place your new packing and wrap it tightly around the inner core tube.
  5. Slide back into the exhaust pipe.
  6. Replace the outlet cap and the slip-on.

Check Your Reeds

Your reed valves control the air and fuel mixture that goes into the cylinder. As the piston rises, it creates a vacuum in the crankcase. The reed ensures that the mix won’t move back into the carburetor and only moves in one direction from the carburetor to the crankcase.

Reeds should ideally be checked every 10 hours of riding and replaced at least once a year. If your reeds are worn or damaged, you may have difficulty starting your bike.

Check Your Fuel

Always use fresh, high-quality fuel with a suitable octane rating for your particular dirt bike. Refer to your owner’s manual to ensure you are using the right fuel. Octane 87 is acceptable for fuel injected 4-Strokes, but in a 2-stroke, the best gas would be an ethanol-free 92 or 93 octane.

A lower octane can cause pinging or knocking noises caused by detonation when your fuel burns too fast. Try your best only to use non-ethanol blends where you can, but never have more than 10% ethanol-based fuel.

Conclusion

Dirt bikes are a hands-on affair with more frequent checks, tweaks, and required changes in other types of motorcycles. One must bear in mind the unique functions of these small but seemingly indestructible machines and the off-road experience.
It’s no surprise that some of the top MotoGP icons, such as Valentino Rossi, have a motocross background. For some, it’s the ultimate riding experience. You just may have to put in a bit more work.