Hilliard Extreme on HF 2.5 shearing off keys

My friend (who is not so PC literate) has put a HF Greyhound 2.5hp on a Schwinn Skyliner. It has a 10T-to-25T primary and a 10T-to-44T rear drive for an overall 11:1 ratio, which gives a modest topend of 25MPH. He's using a Hilliard Extreme (2300 RPM engagement) that has the built in key. It has sheared off TWO of these keys after just a short time (he had an extra hub). He weighs about 190lbs. and I'm guessing the bike is 75lbs. or so. It appears that he has installed it correctly.

Has anyone had similiar experiences with this clutch? Any ideas as to what's wrong? Does it need a lower gear ratio?

P.S. He has some 1500 RPM springs (and a new hub) ordered and hopes that will make a difference.

Thanks in advance....

OK, a Max-Torque has been ordered and we hope it does the trick. I've suggested also that he do a little pedaling on take-offs so as not to stress the clutch so much.

LS614 said:

I know that the EZ transmissions are pretty much indestructible, so tell us how it all holds up, your key may still be a weak link, but the key is much easier to replace than the clutch

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With the mechanical advantage of the CVT you would expect the clutch not to be stressed as much and we will see how the MT holds up with his jackshaft setup. He has it on now and says it's smoother than the Hilliard. But he only has a few miles on it so far.

I agree it's a quality problem...these Extremes are supposed to be for engines up to 13HP. What a joke! Apparently can't even handle 1/5 the power. He bought it from Northern Tool and they did replace the first failed unit under warranty. We may try for a refund but aren't optimistic.

It makes you wonder if they are selling factory seconds or something. We have Hilliard's phone, so we may try to get some feedback from them.

An update:

My friend has put over 300 miles on the new Max Torque clutch and all is well. The Hilliard Extremes are just CRAP clutches!

Yeah, I saw your earlier post and that sounds interesting. My friend is 200 miles into a 1500 mile trip, so we'll keep those mods you mention in mind. He has an extra MT with him but if he has any trouble with the first clutch I think a beefier backup would be a good idea.

Mfgsupply.com does sell the Draggin-Skin racing clutches but not for a 5/8" shaft. Plus, they are a bit pricey. Guess I'll contact MT and see what kind of a turn-around time we could expect.

Thanks!