hydaulic clutch fade

[firffighter]

Hey I just got back from a week long trip to Vancouver Island, B.C. where we rode 3 days. The island has some awsome riding areas with a lot of variety and very challenging. On our first ride we did some tough single track with some killer hills mixed in. We rode for about 4 hours and I found that the last hour my clutch was fading badly which is no fun on tight trails. This was my first ride on my '99 200 exc ( which is an awesome bike ), and the first time with a hydaulic clutch. I check the fluid level which was fine. I adjusted it all the way in on the adjuster which still didnt help. We rested for about 20 minutes towards the end and after the rest the clutch worked better, but still would have a hard time finding neutral. Is this a common problem to hydaulic clutches or do I need some new clutch plates. The other 2 rides were less time and less challenging and the clutch worked fine on those rides except finding neutral after a while. Any advice or help would be greatly appreciated. Sorry this thread is so long.

 

[Matt R]

I would try putting in fresh fluid in and bleed all the air out. Typically, it is DOT4 but check your manual or on top of the reservior cap. Last year, I redid my brakes and clutch fluids. It made a big improvement on how the controls felt. It sounds like your clutch (and I would bet your brakes too) are getting mushy due to water absorption and air.

 

[elf]

Putting brake fluid in a ktm hydro clutch is a big no no. The clutch uses mineral oil. But fork oil or atf will work just fine. The brake fluid eats the seals.
If your clutch is fading more than likely its the plates that are worn. A new ktm hydro clutch wont fade even with lots of abuse.

 

[Matt R]

Putting brake fluid in a ktm hydro clutch is a big no no. The clutch uses mineral oil. But fork oil or atf will work just fine. The brake fluid eats the seals.

Thanks for speaking up about mineral oil. I didn't realize KTM used mineral oil in the clutch (those are Magura's right???). On my GasGas, the clutch is AJP and uses DOT4. The newer AJP's on trials bikes use mineral oil too.

Like Elf said, you definitely don't want to interchange the two fluids... bad for seals. The reservior cap should state the fluid to use, so when in doubt always check there before filling.

 

[firffighter]

thanks for the advice. I didn't think a hydo clutch should fade. I'll try new fluid, then new plates.

 

[lawman]

while you've got it apart, you might conmsider replacing the aluminum clutch plates w/ steel 1s. I had 2 200s, & in my experience, the alums let go w/o warning, then you've got a slipping clutch.