mx engine component replacement schedule

[gibsojs]

I have an 06 with HRC that I have run for 3 years, B motocross. I have performed all ruotine maintenance, air filter , oil change, piston rings etc.

Realizing nothing lasts forever, does anyone have any experience as to how many hours can be logged before the other major engine components should be replaced/serviced?

Specifically , piston,crank,main crank bearings, connecting rod and bearings, timing chain,transmission/clutch components.

[eastside 400]

the only schedule you can go by is when something wears out and you notice it, you cant put a schedule on those parts really, trans would only need to be replaced when it skips gears or you split cases and notice wear, cranks usually last 1-2 years in my experience but they could last much longer, next time u have the cylinder off but measure the play at the rod with a feeler gauge, timing chain is cheap insurance, never really heard of failures but i always replace when doing engine work if its been in for a while, clutch only needs replacement when slipping, this is easy to check if you want to, you dont need any new gaskets to check clutch plates and fibers. pistons should last a very long time if you re-ring them just check the wristpin and journals when you do. your probably going to need to redo the head soon, new valves, springs, cut seats, seals etc.. if you have three years and are getting ready for another season i would suggest tearing the motor down and replacing all the bearings/seals, crank, check cylinder, new piston/rings, head redone, new clutch.

i always tear my motors down after every season and replace everything at once, its cheaper in the long run before something breaks