way to unseize a seized engine? please help!

Hard to diagnose without the bike in front of me,but I encountered a similar dilemma. I bought a CB550t with a locked up motor. I sprayed some penetrating oil (the name escapes me,but I can do a deep inner cranial search,if you are interested) in each cylinder,and toted the bike around on the back of my truck for about 2 weeks. The constant agitation of road irregularites (and the fact that my truck REALLY needs new shocks) did the trick. 120lbs in one cylinder,125 in the other. But now I have to find something else to use as a boat anchor.

 

What have you bought there, Schoot', is it a compleat bike, a rolling frame, or just the mill?

 

The oil in the cylinders should help and try to "bump" start the bike. Try her in 3rd gear and get someone to give you a good push. That may break her free.
I rebuilt an old 871 GM "screaming jimmy" that was seized up, turned out that the PO had installed one set of connecting rod bearing sleves in backwards and the the friction on that one journal was enough to prevent the engine from turning over. May be something simple like that??????

 

Don't try to bump start it if it's stuck. My bet is on a valve being stuck open (probably exhaust) and it's hitting the piston.

Take the rocker cover off and see if there is an overly loose tappet. That will be the one.

Come back if you find this and I'll run you through how to free it.

 

Thats what I'd do. Visually inspect EVERYTHING first man.

 

I second that. You need to inspect and find the problem. Don't force it you'll make more work for yourself if you do.

 

This motor is currently in the frame, I guess, so it would be a bit hard to invert it upsidown and gently try to turn it over by hand, maybe some object got jammed in whatever chains are in an old CB.

If you then can turn the engine over, you have to go in and find the "object". Maybe laying the bike completely over would have the same effect.

How about buying a running bike?

 

I have used Automatic Transmission fluid in a couple of old inline v-6 truck engines. Put a couple of ounces in the spark plug hole let it sit overnight. It would smoke like hell for 15 minutes or so after it was cranked but it worked everytime.

 

QFT

ATF is the way to go.

 

but my engine isnt seized i htink, theres just fomr foreign or lose thing bloacking something from moving

 

OK Schooter... it's time to prove to us that all the sage advice and wisdom bestowed upon you has not been in vain...some of it has GOT to be sinking in 8O
These guys have given some good advice... when something is wrong with a motor you have to be methodical in your approach. It seems to take longer, but in the end you find the problem and you only have to fix what's broken, and only do it once. You can either be a shadetree mechanic who diagnoses the problem and fixes it.....or a parts replacer who throw a bunch of new parts on hoping one of the new parts solves the problem...after all...even a blind squirrel finds a nut every now and then....

 

Which is more than likely a stuck valve. Either take the rocker cover off and see if there is a loose tappet, or pull the spark plugs and shine a torch in each cylinder while you try and turn the motor. If there is a stuck valve touching a piston it will be pretty obvious.

 

It's been over a month. Whats the verdict?

 

Changed the Flux Capacitor, works fine now... ( No clue honestly, Hope it's running )