Who knows their clutches?

[tsheh4]

Question for the audience,  does anyone know the differences in the hs400 and hs500 primary belt clutche and the wet clutch? I have been told the 500 and up engines use a clutch that is interchangeable with yahmahas, but the 400s have a different part number as far as I can find. Is this maybe just different weights in the clutch? Also does anyone know what the factory weights are? Went for a ride in my 400 this week and looking to see if I can get a little more out of her as far as holding higher rpms and maybe getting a bit more aggressive clutch engagement sooner.

[cliffyk]

Their is only one clutch, the centrifugal wet clutch--I do not know if units with other flyweights available--but that's what would be needed to increase it's engagement rate (at the expense of driveability):

In the HS series he Primary and Secondary CVT sheaves are not clutches but rather a variator (primary) and torque multiplier (secondary)--most "maxi-scooters" (400+ cc) use this type of CVT .

variator:

In the variator centrifugal force flings the weights outward trying to force the pulley halves together as speed increases--this increases the effective diameter of the primary sheave an d draws the belt down into the secondary sheave, attempting to reduce its diameter (I.e. a "higher" (numerically lower) gear)--but in the  torque multiplier (secondary sheave) that action is opposed by the torque spring (and the torque "cam"  and followers)--trying to maintain a "lower" overall gear ratio. They battle it out constantly as the vehicle's torque requirements change.

The torque multiplier cam works because when the belt slips on the fixed pulley half (inboard) it does not on the movable (outboard) half, making the outer half rotate on the hub. As it rotates on the hub the cam grooves try to force the halves apart, increasing the effective diameter and forcing a yet lower ratio--this is the torque "multiplier" function. The cam profile can of course not be easily changed, however the spring can, with heavier springs favouring "lower" overall ratios and lighter springs "higher" gears.

The weights in the variator work similarly, heavier favours "higher gearing" , lighter"lower gearing". But neither are  clutches, despite often being referred to as such.

The only thing that can "slip" and limit engine torque to the wheels (other than the belt which is not likely to) is the wet clutch; but altering the variator weights and/or torque multiplier spring can change the overall CVT ratio making clutch slippage less likely--at the expense of top speed.

[tsheh4]

Cliffyk im starting to figure out you are the go to guy for info on these machines. Appreciate your info very much, on this and a a few other posts over the last week.

I had the concept in my head right, just didnt nail the vernacular. So now a little deeper down the rabbit hole... I need to figure out how much parts interchangeability there is between a yahmaha and my 400, and the weight of the weights in the variator. Looking at a primary variator made by an outfit called hunterworks. They have applications for many different machines, and they are supposedly machined to be able to give you a little deeper gearing on the low end and slightly higher on the high end. They also make weights to attach to the wet clutch shoes to give a more positve and quicker engagement. From what in hearing there is a chance the kits for a 660 rhino may be a fit.... but im looking for some validation before I drop the cash.

[cliffyk]

14 hours ago, tsheh4 said:

Cliffyk im starting to figure out you are the go to guy for info on these machines. Appreciate your info very much, on this and a a few other posts over the last week.

I had the concept in my head right, just didnt nail the vernacular. So now a little deeper down the rabbit hole... I need to figure out how much parts interchangeability there is between a yahmaha and my 400, and the weight of the weights in the variator. Looking at a primary variator made by an outfit called hunterworks. They have applications for many different machines, and they are supposedly machined to be able to give you a little deeper gearing on the low end and slightly higher on the high end. They also make weights to attach to the wet clutch shoes to give a more positve and quicker engagement. From what in hearing there is a chance the kits for a 660 rhino may be a fit.... but im looking for some validation before I drop the cash.

I have heard that (Rhino 660 and HS400 parts interchangeability) as well, but not verified--I have also seen it claimed that Hisun made some Rhinos. though the EPA database does not show this. Looking at photos on the web they "look" the same--perhaps Hunterworks can provide some dimensions--you'd have to take yours apart of course, but that will provide you with the info you need to track down potential upgrades. The wet clutch assembly is held together with Cir-clips so you could disassemble it and play with springs ans added weight. I have done this with a Suzuki Burgman 400 and Honda Silver Wing 600 scooters--pretty much the same CVT but with dry clutches...

[tsheh4]

I've got an email in with hunterworks, will report back when I hear something. They guy is active on some yahmaha forums and seems like a good guy to work with. We shall see.

[Greg Kilgore]

Tsheh4,

Would like to know what happened with getting more out of the hisun beast. 

 

I just got an Axis 500 to replace my CFMoto Uforce.

 

They also make something called "sliders" that takes the place of the "rollers" or weights (part 5 in cliffyk's primary sheave diagram). Or at least they do for the cfmoto.  The cfmoto primary sheave looks very similar. 

 

One word of warning to EVERYONE with a CVT belt. INSPECT THE BELT. My new belt on the moto lasted a 14 months. Then had a catastrophic failure at 35ish MPH and wrapped around the primary and secondary sheaves. Locking the transmission/rear tires. Sending the wife and I skidding down the highway. Ended up laying it over on drivers side. Luckily no serious injuries. 

 

Cliffyk,

How hard is it to put weights in the clutch. I've seen the Cir-clip that keep the clutch paws in place. But the springs look awful stiff.

[jonlyd]

Has it been confirmed what Yamaha clutch parts interchange with the HS400 clutch parts??