Expect a top end every 4-6 hours, and on the second top end rebuild, full bottom end as well. That is assuming that you look after the engine, keep dirt out, and use a good quality oil, and do NOT go over 15,500 RPM.
Pushing the boundaries…"
"Depends how modified they are. A Chonda - Chinese Honda clone - requires more mods than a Honda but is a cheaper initial purchase. Both can be made faster than a standard KX21 but anything modified will require more maintenance. Although the KX21 is…"
"Hey Mike, do you agree with Wayne when he says that they’re not as competitive to the modified Honda’s? And since they’re no longer apparently being build, would it be better to go with something that’s still in production?"
"Rebuild costs for a KX21? Virtually nothing. I've owned 2 since 2008 and changed valve springs once or twice a year and a spark plug once a year. Oil change every two races. Choice of engine can very much depend on where you race. If a standard…"
"I think tag will be more expensive even running a few times a year . one thing that will happen with tag is you will be racing against guys who have loads of experience. I have raced both 2 and 4 stroke over the years and personally think for our…"