Stuck something inside motor. Help

I ve been working on a frame build for my 1982 xj 550. Three years worth of it. I was going to try to start it today so I took out my spark plugs and put some oil down on top of the pistons and let it sit while I took the stator cover off so that I could roll it over by hand a few times before I tried to start it. However when I tried to turn the crank over it only went about a quarter turn and stopped. Tried to go the other way and got the same result. Xj Wizards unite, and please help me.

 

is it in gear?

FU

 

I don't think so. I honestly didn't think to check

 

How long has your engine been sitting?

Are you needing to break the seize? Put some WD40 in the cylinders and let it soak in.

Very possible you had piston rings rust to the wall of the cylinder ,and depending on where they deattached and then bumped that rust again. ( Who knows, wild speculation never got anywhere anyway.)

My suggestion is to check if it is in neutral, and then spray WD40, or any other rust penerator down. You can also try putting it in gear and rocking it back and forth to see if you can get it moving that way.

 

Get the valve cover off & check there is nothing untoward.

 

I was wondering about that too. If you've got a piston near the bottom or top it takes a lot of crank rotation to move it much. You might just have a ridge of corrosion on the cylinder wall.

 

Don't use WD40. It's a Water Displacer, not a rust penerator. Use PB Blaster, Kroil or Marvel Mystery Oil.

 

"However when I tried to turn the crank over it only went about a quarter turn and stopped. Tried to go the other way and got the same result."
so if the crank goes 1/2 a revolution, a piston could go from the bottom to top.
i'd lift the cams out and try again

 

I'd assumed he got 1/4 then back 1/4. You're right, if he's getting 1/4 each way from his start point he's got a piston doing full travel.

I was under the impression the engine hadn't been touched since it ran. I suppose it'd still be possible that a valve is sticking.

 

kind of hard to tell from the description how far it turns but if the ignition rotor is stopping near TDC or 180 from TDC then the valves are in danger, or at least one of them

 

Pull off your carbs + exhaust and look in with a flashlight, as well as down the plug hole. see if you can see if a valve is bent or hitting. If not, check your timing.

 

Was there and engine top end refurbishment? On a rebuild I had a temporary problem with the cam chain binding on the crank. Appears that the cam chain guide and/or slack in the chain was causing the problem.

 

thanks a bunch guys it was just in gear. I had put some oil on top of the cylinders and when I put it in neutral and tried to roll it over it was still stuck but gave up easily.