I saw Kartorbust's response above in a different thread but didn't want to highjack it. I had started another thread a while back but it didn't get much traction. (see what I did there? )If you're going to run a high HP build, a 94c Duster will work for you up to 40hp on a 4 stroke build. RBG is running a Polaris clutch or CVTech setup (he's not clear) on his 670 build. The 700 (770, 780, 790) series do not hold up to high power for long term very well.
So I've never seen printed specs for the 94C, but it sounds like exactly what I'm looking for. Is the 40HP/4 stroke mentioned above a Mfg rating, or is it something you have determined through experimentation? None of the other units (40/44/780) even come close to 40HP, let alone for a 4 stroke. I assume that is due to the power pulses from a 4 stoke hammering it versus a 2 stroke.
I looked on Comet's website but don't see the 94C listed... maybe its been discontinued(?), but I see they are still available from several sources.
I'm putting together a stout 440 for a scratch-build mini bike, and it will have all the good billet stuff, forged piston, etc, so I'm going to need something that can handle it. There just aren't a lot of options out there. This mini bike won't be ridden like a typical mini... I'm building it for occasional short high speed blasts down the road, maybe take it to a drag strip for fun.
I called Bully about their 4-disc clutch and they told me it wouldn't handle it... Probably due to liability from so many variables and no way of knowing the end user's abilities, the setup, and other things.