CVT help please??

[wfc]

Hi, I just bought a torque converter with gearbox that came out of a 70's model snowmobile. The guy I bought it from imported it from the States about 30 yrs ago to use on a gokart, but never got around to it. I am thinking of using it on an offroad gokart I am currently building together with a honda gx390 engine. It has forward, neutral and reverse with a disc and calliper for brakes. I have no experience with torque convertors befor now.
My question is: How do I determine how far appart the clutch assembly pully and the pully on the gearbox have to be? It is obviously determined by the belt to some extent, but the gearbox pully opens up, and that changes the distance, so where do I start?
Also, could anyone tell me where I might find some more information on this setup? The only markings on it are on the Clutch pully where it says "Bombardier instant torque" I am adding some pics to show what it looks like. Thanks for your help.

 

[jimh]

Pull the outer half off the engine pulley.With the belt riding in the outside of the pulley on the gearbox, pull the slack forward by pinching the front loop of the belt. You should have 1/8-1/4" gap around the center pin of the drive pulley. The belt will look loose when not running or idling. When the rpms go up the drive pulley will close in on the belt causing it to ride up higher in the pulley and away you go. Nice setup you have there.:thumbsup: Slot the engine mount holes or geabox mounting holes. When you get a close measurement, so you can fine tune.

 

[wfc]

Thanks Jimh,

From what I can determine, the pulley on the motor side closes when it revs up, and the pulley on the gearbox opens up as you drive, is that correct? I will slot the mounting holes on the motor side for adjustment as you sugest. If i understand you correct then with the gearbox pulley fully closed and the belt just fitting I must pull out all the slack by moving the engine pulley forward, but still allow a gap of 1/8-1/4" Would that be correct?

Thanks for the info, greatly appreciated:smile:

 

[jimh]

You're right on how it works. You can pinch the front loop of the belt with the outer half of the engine one off,pull the slack forward. You should have 1/8 to 1/4 gap around the center of the front pulley. I think you've pretty much got it. :thumbsup: And again that is a good looking setup. I like the gearbox.

Just remember the belt will look loose and won't tighten til the drive pulley closes in on it.

 

[wfc]

Hi Jimh,

Thank you very much for the valuable info!! I will set it up as per your recomendations. Yes it realy is a brilliant setup, and very strong. The egine pulley has a label on that says its good for up to 9000rpm!! I wont go near that though. I do believe this may very well be the only such unit in the whole of South Africa.... Not a lot of snowmobiles here as it never snows:wink: The Gearbox is perfect for the kart I'm building, hope it all comes together as well as I'm planning.
Regards and be blessed
WFC