Need Help Snowmoble Engine

Anonymous-0 · Jun 18, 2010

I know this is the wrong time of year to think about snowmobles but here goes. My 16 year old sons best friend has a Skidoo snowmoble with a bad engine. My son and his friend want to fix the engine so they put it into my shop last night. It has a 600cc Rotax engine. The year is 1999. I would like to get an engine manual before we start. Does anybody know of a web site that I could download manuals (hopefully free)? Any thing I should know or watch out for? He was told that the seals are blown. Thanks for the help.

Blackhole49 · Jun 18, 2010

If the seals are blown, make sure you determine why. I have an 04 cat that went through 2 sets of seals before it quit. Ended up having a bad crank. Luckily, my work was under warrenty. Didn"t help being stranded twice, though. I have had good luck with cds for various machines off the internet. There cheap and you can reprint the pages when they get oily.

Anonymous-0 · Jun 18, 2010

Go to dootalk.com forums. More info there on Ski-doo sleds than you could read in a lifetime.

Brad Gyde · Jun 18, 2010

I don't know a lot about the ski-doo's, But... I always get told that they are known for "bottom end" issues.

My dad rides a '97 mxz 583, has to have nearly 3k on it by now (speedo don't work, and he won't buy the part to fix it) But has had few problems so far.

Good friend bought a '98 670? (same as my dad's, just bigger engine) and it wiped the crank out at approx. 400 miles. I don't know if they ever determined the cause or not.. If so, I never heard what it was.

Like everyone has said, make sure that you do the homework and try to find out why the seals are blown. I suppose it could just be they dry rotted, but never fixed that on a newer sled.. (but changed a lot of em due to rot on old John Deere sleds.)

Brad

james rumph · Jun 18, 2010

Here in Michigan we do a lot of sledding.
I rebuild and repair a lot of sleds every winter and the one thing i have learned is never buy after market gaskets ...

When you take the motor apart keep the base gaskets that are under the cylinders. The gaskets have a small hole pattern in them which determines the proper squish.

There is probably 10 different thickness base gaskets for every Ski-Doo motor.

If the cylinders are tore up send them to U.S Chrome for replating. Buy your replacement pistons threw them and have them fit whilr the cylinders are there.

Use Weisco pistons , there lighter , forged and probably $200.00 cheaper then the factory ones.

If you have any questions on this topic just email me , i have rebuilt several hundred of them at this point.

James Rumph

buickanddeere · Jun 18, 2010

There is also a shop is Quebec that refinishes those plated cylinder bores.
As for cost and practicality? That's a 13 yr old sled. The motor job will cost more than what the entire machine is worth.
All to often the home rebuild job goes "bang" and grinds to a halt in 50 miles. The broken parts are repaired but the root cause of the failure is missed. Eg.lean carb/plugged jet, seeping crankcase seals, timing problems etc.
In the current economy. It would be worth looking for somebody with too many toys and too much money borrowed. And look for a 3-5 yr old machine, they go cheap.

james rumph · Jun 18, 2010

That's total B.S a good rebuild will do another 5000 miles. If the sled has different pipes , porting then jetting would have to be addressed.

The one problem they were having in them years was delamaniting intake manifolds. The intakes were cracking and causing a air leak [ lean condition] burning the motor down.

If this is a standard rebuild with new pistons your looking at around $1000.00 total cost. High end number with you doing the labor.

A 98 sled is a good machine and your not going to buy that new of a machine for $1000.00.

If it is busted up then it probably isn't worth it.

Look on E-bay at values.

The Rotax motors are great and will go along ways.

I still own my 98 Mach-Z that i bought brand new. Grant you it's not trail friendly , drag sled.

Ski-Doo builds a great product .

buickanddeere · Jun 18, 2010

There comes a time to quit repairing and upgrade instead.
Otherwise we would still be flying 707's and driving 57 Chev's.

MN Scott · Jun 18, 2010

Still alot of 707's in the air and 57 chevy's on the road. Not everyone can run to the dealer and fork out a pile of cash every couple years.

farmallman · Jun 19, 2010

not sure where your located at but this company has a lot of good parts and whatnot.
Royal Distributing Guelph, ON

buickanddeere · Jun 19, 2010

1 or 2 % rates a "alot" in your part of the country.
Comes a time when repairs cost more than replacement.

Need Help Snowmoble Engine

Anonymous-0

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Blackhole49

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Anonymous-0

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Brad Gyde

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james rumph

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buickanddeere

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james rumph

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buickanddeere

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MN Scott

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farmallman

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buickanddeere

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