XYKD-2 clutch upgrade

Posts: 56

Hi guys and galls,
We run 8 GS Moon XYKD-2 260s (and 5 Xinling 250 (CN250 engine) and we have been having a spot of trouble with clutch burn out.
The problem arises when we ford a stream and get water in the transmission, (I know, going trailing in a buggy, tut tut) the belt slips and over heats the variator and clutch and the clutch 'shoes' get cooked and the resin breaks down and goes course and cumbly and in two cases the so called alloy of the shoes melted!
Is there an upgrade to a harder wearing clutch shoe kit. We have decided that the best way to avoid further blowups is to up-grade the transmissions to cope with commercial work, i.e. some 250km a week in dusty conditions with stream crossings.
I have found in nearly all vehicles the small drain hole under the clutch is blocked by alloy flash and needs clearing and when passing through a stream water shoots up the clutch exhaust air vent in the centre so I have fitted a rubber flap over that to allow the hot air out but not the water in.
So, reccomendations to beef up / re-gear the transmission and anyone know what Yamaha engine they copied as Yamaha parts are a lot better quality.
Peter

Posts: 1893

Run lighter sliders and a heavier torque spring to keep the transmission from lugging. I think your buggies are shaft driven so sprocket changes are not possible, but higher ratio sprockets also have helped me keep the stock clutch in good shape after four years. Reducing the rear tire diameter will also help the clutch at the expense of clearance - This might be worthwhile trade off for you.

Posts: 56

Thanks for that, all input welcome.
Yes we are shaft drive with a differential, (that breaks, the factory are on MkIII now).
Lighter sliders (rollers would help a bit as the RPM would be higher but wouldn't that put extra load on the clutch shoes?
Peter

Posts: 4286

rollers and sliders make the drive pulley change gears quicker , thus putting the engine higher in the powerband.

the rollers re-act quicker than sliders, but might loose a little top speed.

the main sping will help put more pressure on the belt and let the driven pulley down shift quicker.

Posts: 1893

Since the engine would would run higher revolutions, you would get less stalling in the transmission that results in clutch slip. Think about how hard it is on a clutch when you lug the engine in high gear verses putting it in to a lower one. By reducing the roller or slider weights, you are keeping the engine in a lower gear longer before the weight moves to the outside and causes the CVT to "up shift" in higher gearing (lower ratios).

Posts: 1893

Posts: 1229

By using lighter weights in the CVT and a stronger main spring you enable the CVT system to react more quickly. Quicker acceleration response gets you into the power band more swiftly. The Torque spring acts double duty as it puts more pressure on the belt(possibly less slippage) and the clutch downshifts more quickly.

We have supplied this setup for many buggys(mainly Joyner) and have had no long term ill-affects. The buggys respond better and have better acceleration and more torque when needed.

It is worth the consideration.....

Glade

Posts: 1229

One other thing I just came to realize....Your 260 variator is much different than the Cn 250 based variator. It will require 8 rollers instead of the six in the cn250. The torque spring will work in both types FYI...

Glade

Posts: 411

Shrug just snorkle your cvt and not get water in there. Use automotive gasket sealer to make it water tight cover to engine. Cheap fix.