I was just putting my cylinder head back together and when i thought i was just about finished i went turn the pistion and it only turned once and and didnt want to turn again, i followed the book step by step but ended up like this. Dose anyone have any ideas what could be wrong?

 

My guess is that your timing chain is off by a couple of teeth and the piston made contact with a valve.

Make sure that the piston is at exact top dead center and that the mark on your cam shaft is pointing exactly up at 12 oclock. To make sure the piston is at TDC, theres a little cap right behind the left side of the cylinder. Screw that cap off and shine a flashlight in there and find the "F" on the flywheel by turing the crank slowly. Once it lines up with the little mark beside the flywheel, u've found TDC.

That should be your first thing to check.

Try that and get back to me.

Sean

 

Ok now i got the piston to turn but if feels like there is no compression. I can pull the kick start down with my hand. I know that it had good compression befor i swithced cylinder heads, what could be wrong this time?

 

Hmm, mine did this once too, and it was from the camshaft being off 180 degrees. So get down to the cam again, and undo the 2 bolts, spin it freely 180 degrees. Then bolt it all back up and you should be good.

Another possibility is that the timing chain is still out by a couple teeth.

Did the machine want to run at all....??

 

I dont even know if it wanted to run, i only put the engine back in and pushed down on the kick start to see if it would turn the piston right and it just went down to easy.

 

You said that you swapped cylinder heads. Has the new one been gone through?
The reason that I ask, is because every symptom you have mentioned points directly at a sticking or warped valve.

 

No acually it hasent, there is not a mechanic around here that wants to mess with it, they say its too old and i dont know what to look for. I still have the other one do you think that i could just switch valves.

 

Today i turn the crankshaft 180 degrees and that didnt work. I tried moving the sprocket a couple of teeth each way and nothing worked. So now im going to try and fing a place that will take the valves off the old cylinder head and put them on the one i just bought for it. Or how hard are the valves to take off and put back in?

Thanks for everyones help, without you guys i wouldent even be this far.

 

THE F ON THE FLYWHEEL IS FOR FIRE YOU USE THE F TO ADJUST THE CDI ON THE SIDE OF THE HEAD, YOU NEED TO PUT THE FLYWHEEL ON THE T FOR TOP DEAD CENTER AND THEN PUT THE TIMING CHAIN ON,YOU COULD TRY TO TAKE THE TIMING CHAIN OFF AND SEE IF YOU CAN TURN THE CAM OVER BY ITSELF,IF YOU CAN THEN ITS NOT THE VALVES.

 

Sounds like you bent a valve when it was out of time.