suggestions for freeing up a locked motor

danno

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I recently purchased a 1978 Yamaha SR500E as a parts bike for the 78 SR500 that I already own. Although the bike is rough (MAJOR understatement here...), it does have a clear title, and I feel it would be a shame to reduce it to parts. The engine is locked up, and I would appreciate any suggestions on how to correct this. The bike has 14,000 miles on it, and the seizure was a result of long term storage in a damp enviornment, as it was a running bike when it was parked. I have have sprayed a fair amount of a product called "Free All" in the cylinder, and have been driving around with the bike on the back of my truck for the past few days in an attempt to distribute the penetrating fluid. I know that may sound crazy, but it worked on a CB500T that I bought a while ago. I would rather not tear the engine apart unless it is absolutely neccessary. Any help will be most appreciated.
 
Even if you get it freed up, it's probably best to tear the top end down. There will probably be a ring of rust on the cylinder wall and rust on the rings and in the ring grooves. A good cleaning and honing should probably be done. I just freed up a 650 motor but it took pounding on top of the piston with a block of wood to do so. Several months of soaking didn't do it.
 
Do the same thing your doing but with Marvel mystery oil. Pull the plugs and get like a table spoon's worth in there and let it sit. It's a really good product it actually penetrates deep into the pours of the metal prob deeper than any other product. I've personally done this with a few motors that sat outside in the elements (non xs's). Then try the old fashion pop start method, that is if it rolls of course:D
 
Anti-freeze. Yep, good old green anti freeze. A friend of mine used to move mobile homes, and the jacks under em would usually be rused and siezed. They would pull the homes off the jacks and gather em up, and once back to the shop let them sit overnight . They would usually turn by hand the next morning. Squirt some in from an oil can or a funnel, let sit for a few days. I have unlocked several engines this way ranging from V-8's to singles. The last one oddly enough was a SR500.
Anti-freeze does 2 things. It lubricates, and breaks down rust. With its viscosity, it penetrates very well.
 
Thank you ALL for your suggestions. I am trying the anti-freeze method, as it is what I had on hand. As 5twins said, the motor should be disassembled, but with a cash outlay of only $150 for the bike, I wanted to try to get the engine running as cheaply as possible. I won't cheapskate on my other SR, as it is in very nice shape. And the motor on that bike HAS to come apart so I can replace a broken shifter fork. Thanks again, guys!
 
danno, how did the anti-freeze work out?

I have a stuck 650 that I just put some Marvel mystery oil in about 10 minutes ago. Hoping that it works.
 
I know this sounds like bulls**t, but try molasses and warm water. I thought it was too but a freind tried this with a 1924 Buick that had been sitting in a shed for about thirty years. Left it for a month, got it freed up. The Buick now runs fine ,good compression, just had a head gasket replaced. Has since done a round trip of about 800 miles without engine problems.
 
You'll have to pull the cylinder eventually but it is supposed to free stuck pistons.
How to make a spark plug into a "Greaseplug"
http://www.cyclepsycho.com/greaseplug/greaseplug.html

You know about http://www.sr500forum.com/forum/index.php ??

It doesn't seem like very much pressure could be applied with any grease gun considering that the hose will blow off the grease zert with ease. Pouring ATF into the engine and then using air pressure instead of grease pressure would be more likely to move stuck pistons. That said, we used to use air pressure to keep valves on car engines closed so that the seals could more easily be replaced and I never saw a piston move.

And that was on engines that were running-- not siezed.
 
I know this sounds like bulls**t, but try molasses and warm water. I thought it was too but a freind tried this with a 1924 Buick that had been sitting in a shed for about thirty years. Left it for a month, got it freed up. The Buick now runs fine ,good compression, just had a head gasket replaced. Has since done a round trip of about 800 miles without engine problems.


The main ingredient of molasses is sugar. Ever hear of what happens to engines with sugar inside?
 
danno, how did the anti-freeze work out?

I have a stuck 650 that I just put some Marvel mystery oil in about 10 minutes ago. Hoping that it works.

The Marvel Mystery Oil worked. My engine was froze solid and wouldn't budge. After about 12 hours it moves, still very stiff and slow but it moves. We are planning to move forward and do a complete tear down and rebuild.
 
It doesn't seem like very much pressure could be applied with any grease gun considering that the hose will blow off the grease zert with ease.
Haven't tried it on an engine yet but it works on stuck brake calipers. I have freed up at least 5 or 6 with a grease gun on a zerk fitting. I have a stuck XS650 engine or three hmm....
 
Kinda off the subject and will sound like total bs, but I was having trouble getting new grips on. A friend suggested PB Blaster. What??? A lube on grips? So I tried it, gottem on, and let sit over night. Them SOB's are not coming off. It must do something to the rubber. I had to cut them off when I changed my old clutch perch. I put my current ones on the same way. Solid. I tried my hardest to twist them. Nothing! Not a bit.
 
i,d flood it with penetrine... or flood it with rp7 both are used in heavy engineering and toolmaking ... and would work well ..flood the cyclinders and let them sit for a while after that while its still in the cyclinders try to gently rotate the motor .. .. regards oldbiker
 
Hi, ReycleBill, I have no idea about the long term effects of sugar on an engine. This is an old hotrodders trick to free up old rusty engines. The mix reacts with the rust and turns it back to metal or dissolves it. Not sure which. If the motor is rusty in the piston/cylinder, this could work. Then you drain out the mixture. I've ridden in the Buick I wrote about. I have no reason to doubt what I was told.
 
The water reacts with the molasses to create an acid which destroys the rust. It has been used by restorers for decades (centuries?) to eat up rust and corrosion. A local Yamaha mechanic uses it to derust gas tanks.

The greaseplug should work as long as you can supply grease faster than it leaks out. I'd be careful of putting in a lot of pressure in case it pulled the sparkplug threads out. It would be nice if you could monitor the pressure being supplied. I would think 1000psi would be the most I'd want to put in there. I'd also fill the cylinder with oil, then use grease to supply the pressure, rather than fill the entire cylinder with grease.
 
All this talk of pressurizing the cylinders won't do a thing if either/any of the valves happen to be open.

And what if a crank or rod bearing is the reason the engine is locked?

As for the molassis trick-- I can't say one way or the other but because of the potential damage, after using the molassis, I would want to pull the engine apart and vat it before cranking it. Then again, if I have to unstick it then it's getting a complete teardown anyway.

MacMcMacmac Did you mean 100psi instead of 1000psi ?

The number 1 tool for freeing siezed engines is, always has been, remains, and always will be, patience.
 
Fill each cylinder with vinegar if the pistons are stuck. Once the vinegar is inside the crankcase you'll be good! It'll take at least three days. It will also clean the cylinders.
 
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