Seized engine????

C

colemanbales

New Member
Hey guys, so heres the deal. I had been running my bike without the head nuts/ bolts at the correct torque for a long time, and read somewhere that it was a good idea to torque them to around 120 in/lbs. so i unbolted the nuts,took the head off, and used two nuts tightened together to torque down the bolts. everything went fine, and i got it all back together and torqued down the nuts as well. once it was together, i realized that the engine would not turn over (great timing right....). Its only when i have the clutch let out that this happens, when the clutch is in i can still ride it like a normal bike. so i took the head off of the engine, and saw that sure enough the piston would not go up or down, and the back wheel was locked when the clutch was out. I thought this was particularly strange, because everything worked fine as i was working on it,and before then, but as soon as i had torqued the bolts and nuts, it wouldn't go. I also tried removing the bolts all together, but no luck, it still wont budge. Any ideas?
 
You jammed the stud through the cases into the crankshaft.
Back off the studs, seal the threads to prevent air leaks, and rinse all the garbage from the holes you poked through the cases from the bottom end.
Personally I'm not sure if you ruined it or not, but you now have four possible air leaks in your crankcase. I'd split the cases and see how damaged everything is myself.
whoever told you to torque the studs to 120 in/lbs was wrong. Simply bottom them, add a 1/8 turn, and assemble. Use blue loctite if you like.
edit: I see it still won't turn. I would bet you have a large chunk of aluminum broken off the inside of the cases jamming the crankshaft.
This will require splitting the bottom end. Sorry.
Do a search for rebuilding bottom ends for details.
 
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Maniac57 and I agree on about 99% of issues. Here's one where we don't. I torque all head studs into the case, 120 inch pounds, using the double nut method, and I have never seen what he is describing. I will not say it isn't possible but I've built a few engines in my time and never had a stud punch through to the crankcase.

To test is easy. Just remove the studs and see if the crankshaft rotates. If it does he could be right. If it doesn't you have something else wrong. I can't see a little debris that might have fallen in keeping the crank from turning. How much force did you use trying to turn the crank with the studs removed?

Please let us know what you find. It will be interesting.

Tom
 
I guess debris could well be the problem.
I'm just thinking how easy it is to confuse in/lbs for ft/lbs. I've seen two like this. Both used the wrong torque wrench.
 
maniac57 said:
I guess debris could well be the problem.
I'm just thinking how easy it is to confuse in/lbs for ft/lbs. I've seen two like this. Both used the wrong torque wrench.
Click to expand...
Oooooooo. 120 foot pounds? That would do it. I remember a fella back a few years ago who was twisting off head studs/nuts. He said he swore he was told to use foot pounds.

Anyway, I hope the OP responds with whatever he finds.

Tom
 
No offence intended to the OP, it's an easy mistake to make.
Either way, I think he needs another teardown and inspection at the least.
 
No I am defiantly sure inch pounds, but anyway If I end up buying a new bottom end, would you recommend re breaking in the engine?
 
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