So I dropped the motor back out of my bike after rebuilding it. Because when trying to start it, the crank wouldn't turn over. I pulled the heads off and tried turning the crank, that works. But as soon as I attach the cams and timing chain it only allows the crank to turn 3/4 a turn before it stops. Tried several times on timing the cams over and over. Cams are straight, not over torqued. Checked the valves and all have shims and move.

Have no idea what it could be. Going to swap a full set of heads to see if that changes anything.

Thanks all

Stay hard and ride safe

 

Your valves are hitting the pistons. Your timing is probably off. If you tried to start it and the pistons crashed into the valves, they may be bent now.

 

What do I need to time it correctly. Reading the service manual it shows where the cams need to sit. Not the pistons.

 

It should show where the mark is for TDC #1. Since you have the head off, put #1 and #4 up and see where the mark is on the crank gear. You will need to remove a cover to see it.

 

74demon,

Thanks for the advise. Question though, I have a second set of heads. Should I just clean them up and use them in case I did bend anything previously. Than makes a little sense. I might be able to fix that. Just now need to find the markings.

Thanks again

 

Depends on the condition of the other head. Put the best one on...

If you turn the head over, with plugs in it, fill each chamber with water and let it sit. If any valves are bent, they will leak the water into the ports.

 

That's a "leak down" test... ghetto-style!!

But seriously, that's a good way to find significant warpage in the valves, though I personally wouldn't be comfortable until I removed and examined each valve individually.

 

That's a "leak down" test... ghetto-style!!

Absolutely! But it's the easiest way for the "untrained" eye to see if they have bent valves at home...

Actually checking the valve face's contact on the seat is a different lesson

 

Thanks guys. Will let you all know here in a few hours if it starts or not.

 

So the re timing the cams to the crank solved the problem with the crank stopping. But now, the starter can't turn the crank, but the crank will turn by hand. Checked the starter and battery. Both are good. I'm assuming I may have torqued down the heads/connecting rods to tight. Bummer.