Anyone used an ex-snowmobile CVT?

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smokyjoe
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Anyone used an ex-snowmobile CVT?

Post by smokyjoe » Thu Jun 05, 2008 2:21 am

I've a line on a couple of "slightly used" snowmobile CVTs, trying to do the bike on the cheap. Has anyone used any of these on a bike? Looks like it may work OK if I can keep the distance between the shafts fairly short with a shorter belt. Any thoughts?

Fiddler
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Post by Fiddler » Thu Jun 05, 2008 12:34 pm

The Comet CVT i use is advertised as a direct replacement for snow mobile applications, so i see no reason why you shouldnt get good results.
It would be worth doing a bit of research on the units you have though, Hp rating, ratio's etc just to make sure before you start fabricating.

Cheers, Mark

smokyjoe
I luv the smell of Diesel...
Posts: 201
Joined: Mon May 26, 2008 1:42 am
Location: Western Taxachusetts (Massachusetts) USA

Post by smokyjoe » Thu Jun 05, 2008 11:36 pm

Thanks for the info, the one I just looked at today looks like it will fit, 8 inch drive, 10 inch driven and about a 30 HP 2 stroke pushing it. (I've only got 7 to 10 HP of thumpin one lunger diesel) It is on an older 70's sled, with a spare clutch and lots of extra drive parts included (ebay time!) I guess that once I get the weights set, whatever ratio it ends up at I can dial in with the drive sprocket. Can probably get the whole sled for $100, and I think it runs, too.

smokyjoe
I luv the smell of Diesel...
Posts: 201
Joined: Mon May 26, 2008 1:42 am
Location: Western Taxachusetts (Massachusetts) USA

Post by smokyjoe » Mon Jun 09, 2008 10:45 pm

One catch to using the sled drive- I noticed that the driven pulley only has a one way ramp... I guess that the snowmobile coasts when you let off on the throttle? I'm not a snowmobiler, so I dunno, but by looking at it that looks like that's the way it is. Anyhow, I am going for it and buying a complete (I think running) snowmobile for cheap.. Anyone need a 440cc engine or any other stuff? (other than the drive!) I think it is around a 1974 Arctic Cat 440.

Looked over the old '80 Suzuki GS550L today (it is stored at my parent's house) and it seems that I don't need as many parts to fix it as I thought. It took a good spill before I bought it, wiped out the front master cylinder, speedometer, bent the handlebars and left footpeg, otherwise not bad. Looks better than most other bikes I've owned!

Take care

smokyjoe
I luv the smell of Diesel...
Posts: 201
Joined: Mon May 26, 2008 1:42 am
Location: Western Taxachusetts (Massachusetts) USA

Post by smokyjoe » Tue Jun 17, 2008 2:31 am

Picked up a different snowmobile than previously mentioned, a 1972? Scorpion 440, guess they were the thing back in the day. It was recently running, CVT is in good condition and belt, although old looks like I can get a few miles out of it. The driving (engine) unit is 8 inches dia. and the driven (jackshaft) pulley is 10 inches, approx., unfortunately bigger in all dimensions than the Comet 500. I hate to steal the CVT from this machine, but I guess I can always find another driven unit if I want to play around in the winter! Luckily it came with a somewhat buggered driven unit.

As I said in the previous post, there will be a lack of engine braking due to the driven unit's "one-way" ramp. Maybe if I get this working I can either make a new ramp arrangement or fit another driven unit. I haven't taken it apart yet, hopefully there's lots of room inside for more weight.

Also have to rig up a stub shaft or direct bolt on arrangement for the Hatz E79, as it has a flywheel drive. Should be no problem.

I am really sold on the CVT now- after doing some tweaking of the unit on my 49cc 2 horsepower 100MPG Honda scooter (changing pulley to different ramp configuration and playing with weights) I was able to go from 29MPH previously to be able to cruise all day long now at 35MPH! (although that's illegal, as the "moped" speed limit in Massachusetts is 25 MPH) It pulls good up hills now, and the little engine winds up to around it's peak torque and doesn't hit the rev limiter unless going downhill. Gas mileage seems to be better than before the changes probably due to not riding around with the RPMs in rev limit.

If only I can have as good of luck with the Hatzuki (as I'll call it) drive I'll be happy!

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