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I didn't even know there were different size ring gears for the Rotax.
 

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Discussion Starter · #23 ·
Again go to the swap meets and find the parts you need
I can already find parts, I just don't know if they will fit what I have.
What I have is slightly unknown, unless I can figure out how to remove it from the engine.
I know I need the long extractor bolt but don't know which tool to order.

For now I'll focus on getting it to run, if that makes it easier to start then I wont bother with the starter.
Plan on trying again today.
 

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Discussion Starter · #24 · (Edited)
I tried and couldn't get it to pop even with ether directly in the plug hole.
Compression test showed 50 psi on the pto side cyl.

pulled the engine today.

Stripped sparkplug thread on the fan side head suggests a very lean run and severe overheat .
no damage to either head internally.
I took a quick video with my phone.
I did find the gasket, seems to be O ring seals.

 

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Really should be a metal gasket for the head.

You're going to need to get that cylinder bored out or replaced. Might see if you can find a replacement first, as boring might cost as much as a replacement.
 

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Savoy1 here, had to register again as gerard when I lost my password info.

I did find what looks like rubber O ring in the top of the cyl.
Hopefully they will be included in a gasket kit.

I've found lots of used cyls online, could always do that.
A retired neighbor who ran sleds for years here (northern Maine) said he honed his and it was good, he thinks we should try it. if it doesn't hone up ok I'll not bother reinstalling it.
 

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I found a cyl and piston on ebay for $139, does it matter which side of the engine?
the listing doesn't say fan or clutch side and I thought there is a difference but don't know enough about these things,
The clutch side cylinder is what went on mine.
Heres the listing.
Also it says 380f
Mine is a 1996 e380, is there a difference?

 

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I have sent them over sized pistons and they can bore it and replate it over sized!
I have had a 580 bored out to 625? or so
Comes back even better than new!
I would too but social security doesn't leave enough money at the end of the month.
If they give us another stimulus check, then I'm all in for rebore on both side .

For now, we're gonna try clean with muriatic and hone it, if it won't hone i'll get a used one.
I only have a decent caliper for measuring but both cyl seem to be 62mm.
Fan side is all original, AUS mark on piston , it just needs rings.
The damaged side has a replacement piston with STD marking.

I flipped the block upside down and spun the crank, nothing fell out.
 

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Like KC said. The biggest issue with pistons is the skirts. As they wear, piston slap increases to the point that the skirts get thinner and can break off. When that happens, it's usually pretty catastrophic. I had one on my 700 let go, sent chunks of piston skirt through the crankcase. That was about a $2500 repair for all the parts that it needed to get back on the snow. Some engines are more prone to piston skirt failure than others (mid-90's ZR 580 engines from Arctic Cat are one of the worst, for example.) Smaller engines seem to go longer than larger, though.
 
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