hi everyone.... new member to the yamaha club never been on any bike forums before so be nice

main reason i joined is because im having trouble with my thundercat.

I have given her a complete engine rebuild after destroying her unusually fragile gearbox and im now in the final stages at last......

But as soon as i tighten up the camshaft holders the engine starts to bind when its turned over.

I am baffled the cause of this problem has eluded me for about a fortnight and now i have no idea wot to do other than go to a dealer and be conned into spending wot litlle money i have left in my bike budget.

Any help will be much appretiated and i will try to give as much info that is neccesary to solving the problem....

thanks

is the engine locked hard or just difficult to turn over?

camshaft holders I assume you mean cam caps?

Yeah its just hard to turnover.

They might be caps, i only know them as holders... the parts that actually hold the camshafts in place, if thats what you mean.

Yeh thats the caps " so your turning the engine to line up timing marks ? are the cams tight to turn ? without chain on them ,,,

No im just turining the enigine to make sure it turns. I took the cams back out and it still sticks with just the top of the engine built up.

If the cam chain isn't getting bunched up,and the clutch basket isn't installed,then the last place to look is the stator,if installed, possibly a washer or someting magnetic has gotten in there.

If not pull the head back off and start over making sure everything turns smoothly befor the next piece is installed.

Yeh as DT50 says" av head of things dropping in plug hole and locking engine,,, i wouldnt build up engine till its solved,

hi all just to let ya know i sorted the problem not sure what it was but stripped the engine down and rebuilt it bit by bit really slowly and it turned over fine so happy days..... will quickly inform the owners club if i have any other sort of problems....

Well done piedude