Yfm200 wont turn-over, need help!

[200yamaha]

hi, ive got a 86 Yamaha yfm 200 (moto 4) , and problem im having is it wont turn over. its like seized up. it was making alot of "ticking" in the head so we thought maybe it dropped a valve. so we started to take the head off and got theboltsundone. i go to pull it over and it turns over now! put it back together, then wont turn over

any ideas? idk a whole lot about these, but ive heard the valves need to be adjusted over time, could that be a cause?

thanks!!

 

[brandoz28]

will the cam turn in the head?

 

[200yamaha]

Ya it only turned tho when the head wasnt totally bolted down

 

[brandoz28]

pull the head off completely, and check everything out. what did the timing chain look like?

 

[200yamaha]

Ok, the timing chain looked good

 

[Larry's Shee]

Either stuck valve or sadly bent. If it's not to late check cam timing to see if it jumped. Finish pulling it off now cause gasket is probably junked.

 

[Blaaster]

Sounds like you got a bent over valve or something that is fouling the piston a TDC.

You should take the head completly off to see what is causing the problem.

 

[200yamaha]

we cant take the head off all the way. how do we go about disconnecting the timing chain to take it off?

 

[Larry's Shee]

Guess you need to find a manual. DL or paper

 

[Blaaster]

Can you not remove the cam sprocket and get the chain off that way.

 

[Blaner]

we have one these things, it started ticking but was still running, and we stripped and found the timing chain was worn and the slack was knicking the alloy as it turned.

Get the chain off the cam pulley but dont let it fall down into the crankcase, use a cable tie ans zip it onto something to keep it up.