With 4-stroke motocross and offroad bikes taking over today’s racing, I figured give some advice and tips to keep your bike running strong. First and foremost, these bikes aren’t like the dependable and bulletproof 4-strokes of the 80’s and 90’s. These bikes do need maintenance, and you’re always one small mistake away from engine failure and a possible $2000 rebuild.

So here is a list of stuff that I figured you should know, so you don’t regret your change from the trusty ol’ 2-stroke:

They run hot! – You can’t just start your bike and let it idle for 5 minutes without losing some coolant out the overflow. It’s not the bike’s fault that there is no air moving through the radiators. 4-strokes don’t need to be “cleaned out” like a 2-stroke. There is no need to constantly rev the bike on the start line creating more heat and possibly puking coolant all over the cement in front of your rear tire! You only need to warm the bike up enough to warm the oil to operating temperature.

Don’t bounce it off of the rev limiter – I see this far too often, and it drives me nuts. Instead of up-shifting down a straight, guys leave it in a lower gear revving the piss out of the motor. All this does is create more heat and less power. Unlike a 2-stroke, the 4-stroke power curve is more broad. This is good, but it’s also hard to feel when the power curve starts to drop off. Consequently, a lot of riders ride in the range between peak power and rev limiter. They should instead be in the range just below and above peak power. This is just something they need to adjust and it will improve their results and reduce the maintenance costs. Also, don’t hold the bike wide open in the air bouncing it off of the rev limiter, it’s just dumb.

Check your oil – Most bikes today have relatively little oil in them , which reduces the drag on the motor and creates more power. Remember these are race bikes, they require constant attention. Most 4-stroke engines need to be started for a short period in order to check your oil level, so refer to your owner’s manual for your specific bike for the proper oil checking procedure. Proper oil level is your number one defense from getting that unexpected engine failure.

Check your valve clearance - Don’t be freaked out, it’s not hard to do. To check your valve clearance periodically, it honestly may take you ten minutes each time. So don’t be scared, pull that tank and valve cover off and check the clearance. Follow the instructions in your owners manual, and check the clearance with a set of feeler gauges. Now if you are out of spec, then maybe you will need some help. But honestly you should be able to check your valve clearance on a regular basis and you will see when the clearance start to tighten up, then you can schedule a valve adjustment with a shop or knowledgeable friend.

Easy on that clutch – It seems strange, but many guys toast the clutch more on 4-strokes than they do on 2-strokes. This is mainly due to the temperature of the oil. The oil just doesn’t lubricate as well when it’s so hot. Some guys are hard on 250f clutches, while other guys are hard on 450f clutches. The 250f guys may just be slipping the clutch too much coming out of corners, while the 450f guys may be controlling the power with the clutch rather than the throttle. Either way they need stiffer clutch springs. Most stock clutch springs won’t stand up to that kind of abuse. Also the more they slip the clutch, the more heat they make. So not only are they toasting their clutch, but they may also be harming other vital parts of the engine.

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