Gl1500 stuck motor. Can I remove heads in-frame?

[rileysaurus]

So I picked up a NICE 95 gl1500 aspencade over the summer. It hadn't run in a few years and I pulled some water from the motor, as well as the plug holes. The motor is stuck. I've tried to free it up and have been soaking the jugs in marvels oil for months now. I dont see a spot to crank directly on the flywheel. I've removed the alternator and tried cranking where it mounts, but still cant get the motor to turn. From what I could see inside the motor, things are still pretty clean. If I can free up the motor without splitting it open, I'll feel like a winner. Since the gl1500 is a nice flat 6, can I pull the heads off in-frame to access piston heads, or do I need to pull and split the motor? It looks heavy...

[terryt]

If you remove the cam timing belt covers you can turn the engine over from there.

[DenverWinger]

In the front center of the engine (after you pull the tupperware piece below the radiator grilles) is a round access cover held on by three bolts. If you remove it the crankshaft pulleys for the timing belts is exposed. This might be a good place to put a wrench on the crankshaft to see if you can muscle the engine loose.

[MikeB]

If the pistons or rings are what is keeping the motor locked up, trying to remove the heads may not be the route to take. How can the heads be pulled off if the pistons are stuck?

Try using the crank bolt on the front of the engine to rotate the crank.

[Andy Cote]

I want to say I saw a post where someone did it but I can't find it now. My thought would be whether you can get the intake off.

If you can get it into fifth gear maybe you can bump the rear wheel hard enough to break the ring loose.

[bellboy40]

I don't understand your question Mike. The heads are not attached to the pistons. How could the pistons being stuck keep you from removing the heads?
Another option to try to turn the motor over is to put it in 5th gear and try to turn the rear tire.
Edit: I see Andy beat me to the suggestion to put it in 5th and try to turn it over. Guess I typed too slow!

[DenverWinger]

I think you'd get more leverage on breaking the pistons loose with a wrench on the crank bolt. Try doing this before going to the trouble of removing the heads....

[MikeB]

I don't understand your question Mike. The heads are not attached to the pistons. How could the pistons being stuck keep you from removing the heads?
Another option to try to turn the motor over is to put it in 5th gear and try to turn the rear tire.
Edit: I see Andy beat me to the suggestion to put it in 5th and try to turn it over. Guess I typed too slow!

You are correct. I was not thinking.

[bellboy40]

I don't understand your question Mike. The heads are not attached to the pistons. How could the pistons being stuck keep you from removing the heads?
Another option to try to turn the motor over is to put it in 5th gear and try to turn the rear tire.
Edit: I see Andy beat me to the suggestion to put it in 5th and try to turn it over. Guess I typed too slow!

You are correct. I was not thinking.

No problem Mike. I have a lot of senior moments myself.

[MikeB]

I should have given it just a little more thought.

I suppose pulling the heads will give you pretty good access to the pistons and you could probably accomplish it with the motor in place. Removing the exhaust manifolds could be an issue. Exhaust manifold bolts have a tendency to break off. And then there is the intake manifold to deal with. Seems like a lot to contend with. I'd look at removing a head as a last resort.

[rileysaurus]

Thanks for the suggestions. I'll pull off some more plastic and try to wrench on the crank pulley. Hopefully applying some more direct torque will do the trick. I tried knocking the motor loose in 5th gear. After about the 5th time pushing the bike back up my driveway I gave that up.

[Elmobile]

I would take the belts cover off and make sure that those belts are still there... Just in case a valve is stuck in there... then try the 5th gear!

[landisr]

Maybe you have already thought of it, but I would try every way possible to get penetrating oil to all 360 degrees of each set of rings. Simply filling each cylinder may or may not accomplish that if the oil can find a way to leak down. (Maybe I'm wrong here.) My thought would be to fabricate an extension tube for a can of, say, PB Blaster and fog the heck out of each cylinder. Then use a stick of wood and a hammer or mallet to vibrate the block(s) to help the penetrant to do it's thing.

Another thought: Are you sure the rings are the problem? Have you removed the starter to see if it is 'frozen' and/or engaged?

Just sayin'.

I also concur with DenverWinger about removing the timing belt covers. It will give you access to the crank bolt and also allow you to identify any interference issues. In addition, removing the belts might tell you if either cam can rotate, even though only slightly. If that's the case it would tell which side has the problem, thus allowing you to narrow your focus.

Ron in AZ

[Sadanorakman]

I know I'm late to the party, but 50:50 mix of diesel and ATF, or diesel and engine oil makes the most amazing penetrating fluid.
I've seen it free-up farm machinery that had sat rusting for literally decades, and I thought would be scrap.
Might make sense to lean the bike over to the right, and fill the left cylinders through the plug holes, leave it to sit then top it up, then repeat on other side.
Then a breaker-bar on the crank bolt, and a little gentle persuasion.
Are you certain there's nothing catastrophically failed that is preventing the crank from turning? Might not just be seized pistons.

[seelyark1]

How about one that is way late?' If it was put in 5th gear, you don't have to push it down a hill to free it up. Simply rocking it back and forth will do the trick, just leave it in gear, clutch out and rock. Done this with several tractors and it works like a charm, and better than twisting on the crank shaft nut. Can do this with it sitting in the garage.

[CrystalPistol]

So I picked up a NICE 95 gl1500 aspencade … etc … Since the gl1500 is a nice flat 6, can I pull the heads off in-frame to access piston heads, or … etc …

Have not done it myself, but I have seen it done.

How about one that is way late?' If it was put in 5th gear, you don't have to push it down a hill to free it up. Simply rocking it back and forth will do the trick, just leave it in gear, clutch out and rock. Done this with several tractors and it works like a charm, and better than twisting on the crank shaft nut. Can do this with it sitting in the garage.

I have seen this work on old tractors, even old Ford flatheads that haven't turned over in ages. Of course, plugs out, usually a bit of kerosene or other penetrating lube in. Patience is the virtue. The rocking will gently nudge the pistons enough to unstick a ring that's what, 1/8" thick? … enough to let the liquid get in. 5th gear is the gear to use. Don't rush.