Topic: Engine locked up

[Wes]

Hi, I recently got my first bike, I traded an old Snapper mower for it.  It is a 1977 cb550k without a dent on it. When I got it the man said the transmission was froze up, But I new it was the back breaks because, the chain has slack but the wheel still wouldnt move and the pedal was froze. I got that lined out and its shifting. But the engine is locked up. All the plugs and carbs and the airbox wwere on it for the 2 years it was sitting. So condensation probobly froze it how can I unlock this without damaging pistons and rings.

Thanks, Wes

[Lumbee]

...congrats on u'r new aquisition Wes.  There are a couple of methods for this.  Personally I like PB Blaster...u can find it at u'r local auto parts store.  Spray a liberal amount down into the plug holes.  Let it sit overnight, then give the kicker a kick!  I've also heard of people dumping deisel fuel in the plug holes.  Any good lubricant will work...WD40, what ever.  Give it a try and let us know u'r results...

[Greg]

i've heard a lot about these mthods, and since i have a "parts bike" with a frozen engine i have been considering trying some of them.  but, if i pour diesel/wd40/miracle oil down in the cylinders, how do i get it out?  won't diesel quickly kill the engine?  do i just turkey baster it out?
thanks
greg

[natebracing]

Hey Wes...

RaDigga mentioned the easiest method, but just make sure that you're careful when you do it.  I've personally used the "soak and shock" method with mixed results and it really all depends on the amount rust that has formed on the rings and cyilinders.  If too much of the rings have been damaged by the rust, they can break or crack and then you've got big problems.  I wish I could offer some better advice, but short of tearing the motor down, I would follow RaDigga's instructions.

Although, if you do get the motor turning over again, poor some motor oil down in the cylinders in order to lubricate everything while you crank it over.  You want to make sure that the pistons scrape off all of the rust before you try to start the motor.

Good luck brother...



Greg,

If you crank the motor over quickly while the spark plugs are removed, most of the oil will be squirted out.  After that, just poor a little fuel down there and repeat.  Stick some new plugs in and then start the motor.  It'll smoke like crazy for a few seconds but it doesn't hurt anything.

[Lumbee]

Greg...as far as lubricant goes...apply liberally, but its not enough to cause any damage...it will burn off.  As far as the deisel fuel idea, if I recall this person had a bottom end that was locked up, and the motor was out of the bike.  After it was free, they actually fliped the motor upside down, and let it drain out.

[Wes]

Thanks for the help guys I tried it with wd-40. If this doesnt work I'm going to try Kroil or PB. I will be posting pics of my bike today or tommorow.

[Wes]

Its not broke loose yet. Im trying a better oil, i'll tell ya what happens.

[Lumbee]

...if PB blaster doesn't break it, I think u'r next step is to pull the motor, disassemble the head and manually work it loose.

[TwoTired]

 Here is a hair brained idea. 

The kick starter only turns the engine one way.  Perhaps a rocking motion will help get the offending piston free.
Put the bike on the center stand and the transmission in 5th gear.  Rear wheel motion can be tranferred to the cranshaft both forward and backward.  And, the drive train play can help "shock" it free.
You could even use the weight of the bike, pushing it forward and backward in a rocking motion (5th gear).

If you're feeling really dexterious, you could pull in the clutch so the rear wheel turns freely, push the bike to get some momentum, and pop the clutch to transfer the kinetic energy to the crankshaft/piston.  You could do this in either direction until fatigue sets in.  Probably best to have a partner to help steady the bike and keep it from falling over.  Might be a surprise when the piston loses it's grip. 

[Wes]

Good idea im going to try that right now.

[El Taco]

I've always used transmission fluid. Let it soak for three days or so, then put the bike in 3rd gear and rock it back and forth. It'll break loose if it's not too cheesed.

[eldar]

Well if it is that bad, break it loose however you can. You will need to rebore anyways.

[SWMN-CB500]

A guy my son works for just gave me a parts bike for free because he thought the engine was stuck, but it turned out that the only thing that was holding the engine was rust in the stator windings. Once I took off the stator, the engine turned over easily. You might want to check that if you haven't already.

[Wes]

I have transmission fluid, kroil, silicone lubricant, wd-40, and some soot remover in the cylinders now. If that doesn't work after a week or so I'll do a top end rebuild. Thanks for the suggestion I'll check that.

[clarkjh]

Is that a pick of you bike?  If so it's nice to see I'm not the only one to have a barn door on the front of a 550.  Mines a 74.

Good luck on freeing the engine, on the top end rebuild if it happens, I hope you have an easyer time getting the head off then I am.  3 days and counting and all I get is a woble.

James

[Wes]

Is that a pick of you bike? If so it's nice to see I'm not the only one to have a barn door on the front of a 550.

Ya thats my bike and thats a BIG barndoor. It's got two cubbie holes with locking doors on each side. When I got it it had 2 quarts of oil, a haynes manual, and 2 tarps in it and thats only on one side.

[bearcatamo]

After 5 years of sitting, mine was locked up as well. I poured Marvel Myster Oil in each of the cylinders, let it set a while, then put it into 3rd gear and rocked it back and forth. I was told DO NOT use the kick-starter until it is unlocked as it may break off the shaft.

Barry in FL