2006 crf250x won't turn over after reshimming

[simka]

I decided to check my shims and while was at it i took the top end apart to check the valve seats which i ended up grinding them abit, after putting everything back with the correct shims it wouldnt turn over all the way, it stops right where the cam pushes down on the intake valves(it pushed them abit but not all the way), i thought it was the timing so i put the cam gear 1 tooth back but still stoped at the same spot, so i went 2 teeth back and still the same.. does anyone know what the problem is or have any idea of what else i can try? any help is greatly apprecaited

my timing was correct at first try- piston was at the top, left inspection cover (ignition) is lined up and the cam gear marks are in line with the top of the head and the lobes on the cam facing back.

 

[1989kx250]

that doesnt make sense to me... the only thing i could throw out there is did you maybe drop something in the gears?? is your cam chain hooked up properly?

 

[simka]

yea its really strange, i dont think anything went down to cam chain tower as i put a rag over it to make sure nothing went in, even if it did i dont think it would come to a dead stop at the same exact spot..im pretty sure i hooked up the chain in the same order i took it off..i think i bent some valves trying to turn it over with alittle to much power..thanks for your input!

 

[Ol'89r]

It's very easy to get your cam timing a tooth or so off. If you look at the timing mark on the crank and your eyes are not parallel to the mark, you can easily get it off.

It is also very easy to bend your valves if you try to force the engine to kick over. If it were mine, I would re-check the cam timing according to the manual and then do a compression test to insure the valves are not bent. You will have to disable your automatic decompression unit in order to check the compression.

If you think something may have fallen down into the engine, remove the left side case and it will be easy to see anything that may have fallen into that area.