It may not seem like it, but spring resides just around the corner and that means the Motocross racing season looms large.

Thanks to the resurgence of the 2-stroke revolution, more and more riders have stopped with all the nostalgia and simply turned 2-stroke dirt bikes back into the mainstream. In fact, nearly half of all dirt bike parts we sell go to 2-strokes. Additionally, MotoSport sponsors the annual 125 2-stroke Dream Race at Washougal MX Park and the Nationals now include 2-stroke racing for every Outdoor round that proves nearly as popular as the sanctioned 250 class and 450 class Championship racing. Regardless of whether you ride a 2-stroke on the track or trails, these machines require routine maintenance, and if you have taken the winter off, right now offers a great opportunity to spend some time in the garage and perform a complete inspection for optimum spring performance.

Therefore, read through the following checklist of 2-stroke dirt bike parts and maintenance steps to inspect and/or replace before heading out on the first ride of the year.

Did You Winterize Your Dirt Bike?

If you live in cold climates that keep you from riding year-round then hopefully you properly winterized your dirt bike for the months' long slumber inside your garage. If so, you have much less work to do. If not, well, bookmark 6 Tips for Dirt Bike and ATV Winter Storage for next year and read on for some annual 2-stroke maintenance tips.

2-Stroke Maintenance

Oil and Fluid Change

If you filled your dirt bike with fresh motor oil for storage, good job! You don't need to do anything more on this front other than check the oil level to ensure a proper fill. Otherwise, change the oil and if you rode during the traditional off-season take this opportunity to check the maintenance intervals to see if you need an oil change. For those of us who fuss over the tedium, then we suggest changing the oil even after a few hours just so you can start with everything new.

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Some varying schools of thought exist on what to do with premix. Clearly, if you ride during the traditional off months you have little to worry about but when winterizing a 2-stroke dirt bike some riders drain the fuel, others leave it in. The premix doesn't pose a problem but leaving an ethanol-based fuel inside the gas tank for months on end tends to result in a gummed up fuel system. However, how many times have you heard of a rider having problems leaving fuel in the tank for too long?

For what it's worth, we recommend either draining the fuel system OR using an ethanol free, high quality gas to mix with 2-stroke oil and leave full for the winter months. At any rate, if you left a tank of premix sitting for the last few months and used traditional pump gas you probably won't have a problem, but top off with some fresh fuel and premix before starting the engine. If we're talking a year or more of premix and fuel sitting idle in your dirt bike then expect some issues getting the engine started.

You can use 2-stroke safe fuel stabilizers but not all stabilizers work well with the fuel and premix so keep that in mind when going that route. You may find it easier to either drain the system or use better fuel.

Fork Oil

Many riders put off checking and replacing the fork oil because of the time involved to replace it but running dirty fork oil degrades the bushings and seals much faster than when using fresh fork oil and keeping up on maintenance intervals. Fork oil needs replacing every 15 to 25 hours depending on make and manufacturer so check the service manual and hopefully you wrote down the last time you changed the fork oil.

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Brake fluid

Like the fork oil, brake fluid gets changed according to manufacturer's suggested intervals so if the brake fluid remains within appropriate hours check the levels (use the sight glasses located on the reservoir) and either top off or move on to...

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If you store your bike for the winter hopefully you changed the coolant before setting your 2-stroke aside. If not, flush and clean the radiator system but if you rode the last few months check the maintenance intervals for hours and depending on whether you switched to an anti-freeze for the winter consider replacing with coolant for the approaching warmer months.

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Two-strokes don't have an oil filter or a fuel filter, so all you have is the air filter. Again, if you stored the bike hopefully you left a clean air filter in place. If not, check the hours run on the current filter but it doesn't hurt to start out with a fresh air filter (so easy to replace) and airbox if you have fresh motor oil and other fluids in place.

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We know what you're thinking. No, this was not going to be a quick list to check off as your riding buddies wait impatiently for you to get loaded and rolling. Expect to spend some time on your dirt bike - and the carb. Remove the carb, float bowl and jets. Use carb cleaner until clean and an air hose to remove any obstructions inside the jets. Far easier said than done, we know, but you'll thank us later!

Spark Plug

You may or may not need to replace the spark plug. Most riders run these things down to the nub because replacing isn't all that hard. If you have not changed it in a year than you probably need to but pull it regardless of hours and check it out. If the spark plug looks close to failing, just swap it out - don't try to get the most miles out of it. They always stop firing at the most inopportune time.

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Did you inspect the brake system when checking out the brake fluid? We're guessing not. Look at the pads for thickness, the calipers for any loose fittings, the brake lines for leaks or kinks and finally check the lever and pedal for proper function.

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Gotta check them all! Steering stem bearings, swingarm bearings, and wheel bearings. Clean and lubricate, replace if necessary. Haven't a clue on replacing these little things? Read on:

Tighten Nuts and Bolts

Almost ready to ride! Grab some T-handles and work your way around the bike and tighten all fasteners. You just might find some missing, so replace those.


Check cable connections for stretching and wear, and then lubricate points. Check the connections and ensure the clutch and throttle work properly before heading out.


Don't bother with this if you have been riding and have found the right adjustment but a dirt bike sitting in a cold garage probably needs some suspension adjustments but spin a lap or two before deciding.


Check the air pressure on tires with adequate tread wear otherwise replace faded and cracked tires or those with worn down and broken off knobs. Not sure if your tires need replacing? Read When To Replace Dirt Bike Tires.

Shop all dirt bike tires.

Chain and Sprockets

Chain and sprockets always get replaced together regardless of the condition of the other. If you see any wear and tear like cupping on the sprockets or stretching or a flat wear patterns on the top or bottom of the chain - REPLACE. Rust? REPLACE. Lubricate the existing chain and sprockets if both pass the visual check.

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Exhaust Packing

When was the last time you replaced the exhaust packing? An oft forgotten maintenance routine, if you left the old pack in the pipe it's not a big deal. In fact, if you're itching to get riding feel free to skip this step until you hear that tin can pitch emanating from the rear. Either way, check out How To Repack Exhaust On a Dirt Bike or ATV to see if you have an easy job ahead or a more complex removal process.

It might be all about that braap for some, but many riders love the 2-stroke for the ease of maintenance. That means you have little excuse for not keeping up on all recommended intervals and keeping your 2-stroke dirt bike in mostly pristine condition. Two-stroke maintenance is relatively straight forward and pretty easy to master. However, before getting started get the owner's manual for a full system check based on the make, model and year of your dirt bike.