Originally Posted by Foot dragger
Mine went 8 years, did it along with the second piston. And I raced Supermoto to a #1 plate, so not like I was putting along. I just didn't bang off the rev limiter all the time like I was on a 2 stroke. And I ran leaded gas.
8 years on one set of valves,dang the guys who race em around here go a rebuild a year,then the head is ruined at some point along with the crank,then the cases can crack on a hard ridden race 450 or 250.
RV's dad told us 2 hours is it on a SX raced 250 engine,as hard as they ride em the whole engine can be scrap cases included.
8 years is great,Honda would probably like to see that engine for study purposes. A trail riding buddy got 4 valve/ head/piston rebuilds in on a CRF250X before he threw in the towel and got a 250 KTM 2 stroke.
His son owns a Honda shop. On a busy week they have more then a few of those those 250/450CRF's lined up on the bench for re-freshening.