24 replies to this topic

[gsled04]

Great minds think alike. Im working lots of hours, hopefully I can doo the leak test this week end. I'll post my findings.

[DOO_TINT]

OK, no compression in mag side cylinder.

when the crank only turns 180*,,one of the cyls will not move enough to make compression/btw

[gsled04]

Alright I just finished the leak test. Motor wont hold 5 psi for more than a minute. So I started taking it apart. Pulled the throtle bodies and the first thing I see is the oil line going from the oil pump to the mag side of the motor is disconnected from the oil pump, S#it. Pulled the reeds, big gouge in the mag side piston. Pulled the y-pipe everything looks good on the exhaust side. My guess at this point is a broken piston skirt. In 30 years of riding Ive never seen this, a $2500 motor gone because a .05 cent part failed.

[Jimbob SOS]

Alright I just finished the leak test. Motor wont hold 5 psi for more than a minute. So I started taking it apart. Pulled the throtle bodies and the first thing I see is the oil line going from the oil pump to the mag side of the motor is disconnected from the oil pump, S#it. Pulled the reeds, big gouge in the mag side piston. Pulled the y-pipe everything looks good on the exhaust side. My guess at this point is a broken piston skirt. In 30 years of riding Ive never seen this, a $2500 motor gone because a .05 cent part failed.

My meltdown was a cracked oil line going into one of my cylinders. I feel your pain just examine everything carefully as I almost didn't catch it.

[gsled04]

Ya, this one is just strange. There is no damage to the line at all. It was just hanging there like it had been pulled off. When I put the line back on the pump to see how it fit, it went on nice and snug. I guess it was just my turn. I take my sleds apart all the time to doo maintance, Ive never had a major problem other than just wreaking them. Guess its time to build a motor.

[snolan]

Alright I just finished the leak test. Motor wont hold 5 psi for more than a minute. So I started taking it apart. Pulled the throtle bodies and the first thing I see is the oil line going from the oil pump to the mag side of the motor is disconnected from the oil pump, S#it. Pulled the reeds, big gouge in the mag side piston. Pulled the y-pipe everything looks good on the exhaust side. My guess at this point is a broken piston skirt. In 30 years of riding Ive never seen this, a $2500 motor gone because a .05 cent part failed.

See post no 4.

My son lost a skirt on a piston last season ans had the same exact symptoms. He actuall cracked the case rom a piece o the skirt getting wedged between the rod and the case.

Good luck with it!

[ZaHaDoo]

With the plugs looking good I would say its a crank bearing.

Bingo! Leastwise that is exactly what mine was. PTO crank bearing, a piece of the cage jammed the bearing balls. Could rotate it 180 each way till it came up solid. Did not force it, did not want more damage at the time. Everything else was good inside. Seal failure on both PTP and Mag. MAG would have gone soon. 3800 miles.

[gsled04]

Has anybody seen one of these lines come off before? why arnt these things clamped or zip tyed from the factory. I can tell you right now, my other 2 sleds are coming apart and getting the oil pump lines zip tyed before they get riden again.

[snowpro x]

did you accidently pull on it during some maintenance? im going to check mine and zip tie it,I have had throttle bodies off a couple times now..

[gsled04]

No, thats whats so strange! If you have ever tried to remove one of these lines, you know how hard it is to get off once they have taken a set to the nipple. Then consider the location its a B!#ch just to get your hand down there. It's just sickening, I bought the sled new, its in perfect condition, and now a repair thats will almost exceed the value of the sled.(not much resale value in the mtns).
O'well time to suck it up and tear into it.