Looks like a problem

[mswyka]

We were having a great time running yesterday in the first real snow of the season and part way down the trail we noticed that one of the sleds was not following.  When we went back the 440 Invader had quit for some reason.  After a little fussing and checking we found this present on the mag cylinder.  The engine is now in the process of coming out for a rebuild.  Seems a shame too since the top end was holding coolant for the first time in a few years.  This time however I am planning to scrap the sleeved cylinders and go back to an original non-sleeved chrome pair. 

[mswyka]

The rest of the problem.

[jimvw57]

OUCH!!!! my condolences!! I was always leery of those sleeved cylinders and stuck with the stock ones.

[Interceptor398]

That one left a mark!!  I think the tolerance is different between cast iron and aluminum cylinders.

[Lloyd (ljm)]

 Sorry about your luck.

 Are you sure the sleeves were the issue?

Lloyd

ps Send some snow up north

[gixxer6]

Sorry about your luck.

 Are you sure the sleeves were the issue?

My thoughts exactly.  Looks like a lean condition to me...

[mswyka]

Thank you for your kind words of sympathy.

You are correct.  She was running lean on the mag side.  Had a leak somewhere.  Disassembly did not reveal anything obvious.  Had some dry rot in the carb boot, not sure if they made it all the way through or not.  Mag side crank seal did not show evidence of blow by and still seemed to have some "squeeze" onto the crank shaft and was well lubed.

The comment about the sleeves was more related to the longstanding problem this sled has with coolant leaks around the head bolts.  Cooking the piston is my excuse to rebuild without the sleeves. 

By the way, if you see two sleeved cylinders and one 20 over piston on Ebay - don't buy them.

[Lloyd (ljm)]

 lol Thanks for the warning Mark

[Shawn]

I would go through that mag side carb with a keen eye. All the damage is above the ring telling of a very lean condition at high rpm's under heavy throttle. The heat and detonation was incredible to have eroded all that material off the piston dome and the plugs side electrode.