Comet 44 magnum used with 7 1/2" driven

[MTScott]

I'm considering the switch to the 44, for several reasons, which we don't need to get into, but I'm curious if there is any reason why it couldn't be run with the 7.5" driven 40 series pulley? I've seen a reference or two that suggests the 8.5" pulley is intended for the 44, but does it have to?

Any reason why the 44 wouldn't work with the pulley I have (the 7.5 that came with my 40 series)? Is there any reason why i'd WANT to switch to the 8.5" driven pulley?

 

[Denny]

The only reason I can think of is you would be giving up your lower gear ratios and burning up belts. But other than that I can’t think of any.

 

[MTScott]

The only reason I can think of is you would be giving up your lower gear ratios and burning up belts. But other than that I can’t think of any.

Well... Damn it.

 

[Denny]

Im sorry. And I really like you and your build too!

 

[panchothedog]

What Denny is saying is that with a 7 1/2" driven clutch your initial takeoff gear ratio will be higher than if you were using a 8 1/2 " clutch. Depending on weight, tire size, and sprocket ratios it is quite possible that the 7 1/2" clutch could work fine . Give it a try. The worst thing that can happen is you burn up a belt. $30. If it doesn't work THEN buy the bigger one. FWIW I have 3 karts with
30 series torque converters. One has a 6" driven clutch ( standard ) and one a 7", and on the 3rd I removed the 6" and replaced it with a 7" . It DID give the kart a little more snap from a dead stop launch, but it ran fine either way. It was not burning belts with smaller clutch and yours might not either.

 

[MTScott]

Thanks for the info gents.... I can't seem to find a 8.5" driven built by the chinese, so it appears I'll have to also get the comet brand for that. I might just run with the new driven against the 7.5 and see how it goes. It does make sense to me that the larger driven pulley would be easier on the belts on take off. I'm chewing up the cheap belts right now anyway until I'm totally happy with this setup; however, the cheap belts are probably what is gumming up my TC, so, perhaps I should stop running them.

 

[Snaker]

When someone wants to try different things, I say go for it.
Just understand that its up to you to evaluate and pay the cost of torn up stuff
The larger diameter "gearing" is a big deal.

The combination of drive pulley sheaves positioning and driven pulley sheaves positioning is also affected.
The CVT has mechanical limits of the pulleys at both upshifting and downshifting.
A mfr designed set should have the limits happen at pretty close to the same time.
If the driven hits its limits when the drive is in the middle of flyweight leverage, added stress is put on the driven and the belt.

A smaller driven would have the belt pulled down deeper during upshift.
I don't recall the exact profiles of those specific drivens, but some have area's of the sheave innards that aren't intended for belt contact.
And if the belt is pulled down there, its no good.