At The Back Of The Pack
Arm chair racerFirst time rider
I just in form hauling my moto-ski mirage special back, I was going down a trail and I heard a nasty noise, stoped and pop'd the hood and the motor turns half way and stops, looks like maybe I broke a connecting rod, well at least now I know what my next project is, any one ever rebuild one of these?? any tips?? I've rebuild sled motors before just wondering if anyone has any tips.
86 ATC-250SX, 83 ATC-200S, 1980 XR250R, 1980 moto-ski mirage 377 special, 83 Ski-Doo Citation SS 377, 91 Ski-Doo safari 447, 92 FORD F-250 HD, 4x4, 351W shes a work horse.
Got The Holeshot
Arm chair racerJust too addicted
sounds like it could be a connecting rod like you said. That happened to someone i know and the same thing happened. I have one (377) in my old safari and i love it. good luck with the problem.
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-92 Ski-Doo Formula Plus 583 -88 Safari 377 -68 Super Olimpique 299
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-89 F-150 4" Lift/33s
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At The Back Of The Pack
Arm chair racerAt the back of the pack
I replaced the top end in a 377 a few yrs ago. Taking them apart is pretty much the same as any 2 stroke sled motor.377's are strong motors.I used to beat the hell out of mine doing demo derby against GMAN on a 80 yamaha exciter 440.
At The Back Of The Pack
Arm chair racerFirst time rider
Hey tri-z jim, what kinda sled was 377 in??? I hope it's just a connecting rod, I'l replace pistons/crank bearings anyway(of course) I've been restoreing it this winter, so far it's got new Bosch points/condensers/ingnition coils, new exciter coil, rebuilt carbs(has twin mikuni VM-36's) new fuel pump,new air filter,new seals,new cabels,new brakes, rebuilt clutch,new belt, new primer/lines, new where bars/front shocks, and some other stuff, I'l try to post some pics sometime, the body is in A++++ condition(for an 81 anyway) I still need a new track(it works but it's geting old) and now a rebuild, I've thought about just going out and buying a early 90's sled, but anyone can do that, I love restoreing these old sleds, as far as im concernd the best sleds where made in early 80's, there simple, yet stable, yet proform very well. anyway thnks for the advice.
86 ATC-250SX, 83 ATC-200S, 1980 XR250R, 1980 moto-ski mirage 377 special, 83 Ski-Doo Citation SS 377, 91 Ski-Doo safari 447, 92 FORD F-250 HD, 4x4, 351W shes a work horse.
At The Back Of The Pack
Arm chair racerFirst time rider
Hey tri-z jim, what kinda sled was 377 in??? I hope it's just a connecting rod, I'l replace pistons/crank bearings anyway(of course) I've been restoreing it this winter, so far it's got new Bosch points/condensers/ingnition coils, new exciter coil, rebuilt carbs(has twin mikuni VM-36's) new fuel pump,new air filter,new seals,new cabels,new brakes, rebuilt clutch,new belt, new primer/lines, new where bars/front shocks, and some other stuff, I'l try to post some pics sometime, the body is in A++++ condition(for an 81 anyway) I still need a new track(it works but it's geting old) and now a rebuild, I've thought about just going out and buying a early 90's sled, but anyone can do that, I love restoreing these old sleds, as far as im concernd the best sleds where made in early 80's, there simple, yet stable, yet proform very well. anyway thnks for the advice.
86 ATC-250SX, 83 ATC-200S, 1980 XR250R, 1980 moto-ski mirage 377 special, 83 Ski-Doo Citation SS 377, 91 Ski-Doo safari 447, 92 FORD F-250 HD, 4x4, 351W shes a work horse.
At The Back Of The Pack
Arm chair racerAt the back of the pack
i know they were in the safari for sure,maybe the citation and skandic too, not sure. My track came off a few times over the years.I had to make some contraptions to compress the rear suspension to line the carriage bolts back up.
Super Moderator
Just too addicted
If I'm not mistaken, the 377 is a fan cooled engine. Are you sure the sled didnt overheat and just lock up? Or is it doing this when cold? If it's still locked up when its cold, your in for a teardown.
I had a similar problem with my rotax 503, where my fanbelt was burnt up and I was drag racing. I stopped at my house for a minute and left the sled outside idling, and just as i came out it locked up. Tried pulling it over and snapped the rope (75% of the time thats what your fixing on the damn thing anyway), so I tried turning the crank to no avail. I whipped up a quick RICH batch of premix (like 4 ounces of gas and half a quart of oil) and put it down the jug. Put some of this hogsly magic mystery formula into your jug and start working the crank again, It should come loose. With this little backyard procedure you might be able to save your engine for a few more good rides if you didnt overheat it too badly. I have done this on many older 2 cycle dirtbikes that ran for a good season or two afterward, so it's a proven (if a little caveman like) method.
At The Back Of The Pack
Arm chair racerFirst time rider
I just got to taking the heads off yesterday, found the problem was the right side piston is melted, there's granulated metal all over the cyl but the piston is still complete and the connecting rods/crank are fine cause it still spins over, the reason it wouldnt turn was because it built up a rig of metal in the cyl head. I think the reason it melted is because as was taking the heads off I noticed the right side carb boot has a cut in it, so it was sucking in air making it run real lean, ohh well the snow's melting anyway, by the time next season comes around I'l have one he11 of a nice rebuilt sled.
86 ATC-250SX, 83 ATC-200S, 1980 XR250R, 1980 moto-ski mirage 377 special, 83 Ski-Doo Citation SS 377, 91 Ski-Doo safari 447, 92 FORD F-250 HD, 4x4, 351W shes a work horse.
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