Top end tear down. Curious to know.

[Rickrod3]

What have you guys been finding?
What parts were worn?
What mileage did you do the work?

Tia
Rick

[Crazcnuk]

Rings: may or may not need replacing, and hard to find sometimes

Cam chain: has to be cut to get the head off.

Valve seals: may as well replace as they come in the gasket set with all the other gaskets you need.

Barrels: Depends on wear. Most bikes don't show aprreciable sleeve wear in under 50,000 miles, others may have more experience here. Many have rust damage from sitting for long periods.

Valves: Most can get away with a hand lap, but your mileage may vary.

I did mine at about 58,000kms. My rings were totally shot, over .080 end gap, and the gaps were not staggered. The sleeves were well within spec, figure that out.

After I was done I found out my clutch didn't like the extra power!

[TopCatGr58]

Cam chain: has to be cut to get the head off.

Hey Craz, slight error here. Chain does not have to be cut to get head off, just pull the cams, and the chain will slide down in the tunnel. I didn't replace my chain when I did my topend rebuild!! My rebuild was due to as Craz stated, sitting for many years and improperly setup for storage, lots of rust in cylinders, didn't want to take chance with just trying to rejuvenate old cylinders, so did little big bore kit. Lapped my own valves, replaced the seals, but the guides were fine.

T.C.

[DGXSER]

DBeardslee just did a valve/head repair on a bike with a new to the bike engine, I watched and ridiculed him avery now and then for the fun of it Actually I did help a little here and there. The engine has obviously seen some years and some uhhh.....use. This is the engine we found the oil pump dive gear laying in the clutch cover, the c-clips gone off both ends of the shift shaft fork, I believe another bolt may have been laying about in there as well. We found one valve bent and every one of them needed reshimmed I believe, but that was after a valve lapping. The work completed was head removal, valves all pulled, lapped and new seals. Otherwise, put back together as is. Compression is now about 150 psi across the board.

[Rickrod3]

Maybe youu guys misunderstood me.
My questions are for actual findings from top end rebuilds that were done.
Not advise (although I appreciate the thought) on how to do them.
Not that I know every thing as to how to do them I'm a newbie.
I'm trying to get a sense of how the engine wears.
Thanks
Rick

[bikerphil]

These heads last forever. I've noticed slight wear on the cam lobes and the valve seals of course go bad.