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Discussion Starter · #1 ·
I have a 1971 Ski-doo Nordic with a stuck piston. They both were stuck but i got one free. I sprayed WD40 down in both cylinders and it seemed to do the trick on one but not the other. All the wd40 stayed on top of the piston. I tried rocking the drive clutch back and forth with a ratchet and socket on the bolt but still no go. If you could tell me how to free this ole' stuck piston. Please let me know. Any help would be greatly appreciated.
 

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You might try some PB Blaster, or some penetrating oil and let it sit for a while.
 

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Yep, diesel works wonder, too... doesn't evaporate as fast as WD-40. A buddy and I were working on an old military skandic last year that had the same problem, so we filled the crank up with diesel & filled up both cylinders with diesel & let it sit. The next day she was free.
 

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Originally posted by NightTrain
[br]Yep, diesel works wonder.... filled up both cylinders with diesel & let it sit. The next day she was free.

That's COOOOOOL.
 

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How about taking a piece of hard wood at the same diameter as the cyl,put it down the cyl and tap it with something heavy like a big slegde hammer? might work
 

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Discussion Starter · #6 ·
wow...that was quick! I didn't think i'd get 4 replys that quick! Thanks. About the diesel...If i was to pour diesel in the cylinder, what if some dripped down into the base. Will the diesel evaporate? I don't want to have to take the motor out of the belly to drain diesel out.

About the pounding trick....that could damage the brearings maybe? small end roller bearing and large end bearing on the crank. Once I get the pistons free, i'm going to dump some 2-stroke oil down in the base to lub the bearings and crank. If i could only get that piston unstuck....[:(]
 

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When draining the engine, there is a bolt on the bottom of the engine on the crank case and that will drain the diesel out. You shouldn't have to take the engine out to do that...

-Rob
 

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Discussion Starter · #8 ·
oh....mines old though and I doubt if it has it. The bottom end is alright though. I'm gonna dump some oil down in her and see if it runs smooth.
 

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my old ski doo i got had a froze piston i did the wood idea plus kerosene flush after i got it free and to get all the keresene out i just turned it on its side and pulled the pull rope a couple of time any more info you want because i know what you going through pm me oh yah mine was a 1978 olymique
 

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Yeah, no worries about the diesel. Just drain it out, it's petroleum & all it will do is lube the hell out of everything, and it sounds like it really needs that anyway! lol
 

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The trick is too tap it with something heavy , but not use too much force in the stroke and ofcourse let penetrating oil sit on top of the piston a couple of days first.
 

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I personally wouldn't use force unless absolutely necessary... in the skandic that I described above, that baby had sat for years and years. After a day of soaking in the diesel, I was able to simply begin working the primary clutch back and forth with my hands and it was spinning freely after about 2 minutes of working it.
 

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mudshark- I know the '72 Ski doo olympic 335 has a bolt that you undo to drain the crank case. Im sure since yours is a '71 there should be a bolt down on the bottom of your crank case, probably towards the front where you can drain your crank case. Take a look...


-Rob
 

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Discussion Starter · #14 ·
man...you guys are fast! I didn't think i'd get that many posts in one day. I thought "nobody will want to talk about some old 1971 rig when they can talk about 2004 models! Thanks for all the replies!

I put diesel on top of the piston today. I'm goin to let that sit in until saturday. The other cylinder wont even go back on over the other piston. Theres some gunk on the side of the piston that needs to be sanded and cleaned smooth. Then, i'm going to hone the cylinder. That should do the trick. I tried puttin a socket on the big bolt that holds the drive clutch and tightening it. I thought once she tioghtens up, she'll turn that crank over. Nope! She keeps on a turnin the bolt. I put a piece of pipe on the ratchet to give me more leverage and I dont want to break the bolt off! Hopefully the diesel will seep in. I may be able to get my hands on a big strap wrench. That way I could rap that around the whole clutch. But i would need a metal one...because once i put the pipe on it, it's bound to break in 2! This piston is really stuck!

What about the whole tapping thing? Wont it damage the bearings and such? I dont really like the idea of pounding that piston down the cylinder[|)] Thanks for all your help on trying to get the ole' beast up and running for the first time in 20 years!
 

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Discussion Starter · #15 ·
oh yah...almost forgot. Wide side is the drain plug on of the base? On my polaris wheeler it's in the front. I looked both sides of the motor but there isn't much room from the belly to the base. I dont have a clue where it is. I also have an electric starter to worry about. That could be in the way. If anyone can tell me where it is....I asume it's the same for the olympics, please let me know!
 

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mudshark- The Olympic I have worked on was a single cylinder. I am assuming that the drain plug is probably in the same area as the '72 that I worked on. Since yours is a twin cylinder, I would assume that the plug is under the exhaust manifold. You should be able to get to it without having to take the engine out, which is just four bolts (very simple). let me know what you find...

-Rob
 

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one that works good is to heat the cylinder with a heat gun. not a hair dryer but a good one like what electricians use for heat shrinks. the exspansion and contraction does the work for you. put the oil to it as it cools. also get that crank bolt backed off while you can still do it. hope this helps.
 

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Discussion Starter · #19 ·
ok...the only thing is...I have no electricty in the barn I'm working in. So...i have to rely on battery powered stuff. lol.

I put diesel on top of the piston and let it sit for a day and went at trying to get it unstuck today. NOWAY will it move! I pounded on top of the piston with a piece of wood and a hammer, piston wont move. Pounded on the cylinder with a piece of wood and a hammer. Will not move! What is holding this thing there? I've tried rocking the drive clutch. The only thing I can think of i rocking the flywheel. The piston is on that side and may work better with the flywheel instead of the clutch. If u have ne more ideas i should do, let me know!
 

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Did you fill up the crankcase with diesel? Just dumping diesel up through your spark plug holes probably won't do the trick, you've probably got rust down below as well. Fill up the crank with diesel & top off the cylinders, then plug the intake & exhaust with rags, and put the spark plugs back in. This way you minimize the evaporation as it sits & soaks overnight.
If that doesn't break it loose, then I guess you'll have to try to take it apart. The head should come right off, it's the jugs that will give you trouble. But, if you tap on the top of the piston that's stuck as you're working the jug, it should break free.
As rusted as that sounds, I think you're going to have to at least get those cylinders honed & you'll have to put some new rings on the pistons. But if the crankshaft is rusted down below, you'll probably have to rebuild your lower end, too.
Anyway, I'd just try the diesel route & see what happens.
 
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