Top End Rebuild

[drago52]

Hey everyone,

Can someone explain to me what a "top end rebuild" is and why some bikes require it so often? I've had many bikes, a couple with over 30k and 40k miles and I've never had to do a top end rebuild or seen anywhere in the maintenance manuals that it is required.

What specific parts are needed for a "top end rebuild", is it expensive, and how difficult is it a mechanically inclined person with normal shop tools. It seems like dirt bikes require top end rebuilds quite often, while most sportbikes don't.

[TinkerinWstuff]

It's a two-smoke thing

[Titus]

It's a two-smoke thing

Yuuuup

Still the best racing motor!

[TinkerinWstuff]

What specific parts are needed for a "top end rebuild", is it expensive, and how difficult is it a mechanically inclined person with normal shop tools. It seems like dirt bikes require top end rebuilds quite often, while most sportbikes don't.

generally refers to piston, rings, reed valve, and jug gaskets.

bottom end would be crank and rod bearings.

[TFOGGuys]

4 stroke dirt bikes tend to need top end maintenance regularly as well. Piston, rings, wrist pin, clips, gaskets, valve seals, and in the case of Honda CRF250/450s, usually intake valves and valve springs, as the Titanium valves have a rather limited life span in those particular engines.

[Matrix]

I have been trying to talk my wife into a top end rebuild in order to improve performance and usability.

So far, I haven't convinced her.

[Titus]

I have been trying to talk my wife into a top end rebuild in order to improve performance and usability.

So far, I haven't convinced her.

It's never a bad idea to go for the rebuild when the mileage starts getting high.