max hp for a Centrifigul clutch?

[x-bird]

Bouncing around an idea for my daughter's buggy. I got the replacement coil for the little 3 hp briggs. Got it running, but it's too smoky, needs a ring job. So it's pretty much a museum piece.

While i can install the entire yerf rear platform with the tec and jackshaft, it gives me a couple problems in terms of width and size relative to the mini shark.

I have the rear swing arm and axle from a baja 90, including tires--which are more appropriate size wise to the chassis--- sprocket and brake rotor. I'd like to be able to use this axle and part of the swingarm connected to the Tec. It'd be a lot easier if i could just run a centrifugal on the tec right to the sprocket. The sprocket is smaller than the yerfs and is a different pitch that might be an easier match to a centrifugal. I'd resetting the governor/carb to back down the top end until she's ready for it--if needed, the 90's sprocket size might de-gear it enough-- but it'd probably outrun mine in the first 30 feet.

Would a centrifugal hold up to the 6.5 Tec running at about 70-80 percent (probably around 3,000 rpm) or full rpm??

[joekd]

Yes, a typical centri clutch will handle that fine, I was putting 11HP @6000+ RPM through a Max torque one that was like $25 to buy brand new plus there are tons of good go kart racing style ones out there that can handle like triple that power if you want to spend the money

[AceFab]

Joekd is absolutely right. Most of the clutches that are in the $25.00 range are rated up to 8hp. Tire size and axle sprocket size will have some bearing on how well it works and longevity but it sounds like you should be fine for your application. I just bought a Hilliard Extreme Duty for the buggy I'm getting ready to build for my son. It's rated up to 13hp and the cost on it was $39.00.

[metalstudman1]

x-bird- How big of tires are you trying to run?
Acefab said it well- most failures/short life come from "Too" big of a tire and too high of gearing when trying to climb hills. The smaller diameter tires are best and lower gearing keeps the clutch from over heating when on terrain other than flat ground. The key to this type clutch is to get engagement and staying there for several seconds for passing air to cool it off some before having to slip again. Pay attention to the engagement speed recommended on the clutch to know if governing the engine down will effect it.

[x-bird]

The ATV tires are 16-inch.

I got SSMike's 6-inch driven yesterday and cut the jackshaft plate to make it work (cut it so the jackshaft has 4 mount holes and the engine bolts directly to the frame mount. Worked with just enough room to adjust everything.) I think it will work with the TC, if not, I can always eliminate the jackshaft and TC and run just a centrifugal.

The picture shows roughly what i have in mind. The swing arm would be flopped over 180-degrees and welded underneath the engine mounting plate. The rear frame mounts on the main frame of the Yerf match the little swing arm perfectly. I think i'm going to chop only the engine mounting plate out, the ATV axle/tires land right in the existing Yerf side frame rails, so i've gotta have clearance. I still have to come up with a way to get shocks on it.

I have a plan and metal for the yerf to get a new rear frame rail and some beefy mounts for the GX rear frame.