Why clutch gone in 10hrs?

[Spokes574]

new xc 300 Y09 with 10hrs and the clutch is gone- why?
I changed oil 1x using 10w 40; manual says to use 15w 50.

I ordered a new clutch $220, 10% stiffer spings, and made 0.053" shim spacers for the springs to add more stiffness.
Also bought 15w 50 Mobil1 oil. Plan to put together later this week. Plan to but the more agressive power valve spring to let power on soon so less clutch need.

Concern as to why clutch went out in 10hrs on a new bike? my son said he only dabs the clutch once in awhile out of corners nothing like a 125 bike.

any advice, I would apprecate it.

Spokes574, California

 

[whenfoxforks-ruled]

Your inner and outer hub could be out of spec. Check for a sharp edge, or warpage. Vintage Bob

 

[Ud Luz]

When you put everything back together make sure the clutch is retracting all the way. Also make sure the clutch line isn't pinched or kinked. Bleed the clutch in case there's air in the lines.

The KTM 2 stroke has a robust clutch. There's little that can go wrong.

10w40 should be fine. I use Rotella T in mine with no trouble.

 

[Spokes574]

The FIX:
-I bought a new clutch, 10% stiffer spings, 0.053" washer shims
and most importantly purchased the oil KTM recommends 15w50 Non Energy Saving.
I found it at Walmart : Mobil1 $22 5 quarts. Essentially desiels engines use this wt.
Key thing is the Non Energy Saving seal in the back of the oil bottle has less additives.


Have not had an issue with the new clutch at all. The hydrualic clutch makes pulling in the stiffer clutch easy.

The old clutch was in spec but the steel plates look black and very slippery.
I soaked the fibers in gas for 30min, then dried with clean towel, the steel plates I sanded down to remove the black shine and to add some roughness back to them. When the new clutch wears out in the future, I will try to use the old clutch and hope that it will still works. That will save me $220!

Spokes572
Pleasanton, CA

 

[whenfoxforks-ruled]

Good to hear, and keep changing that tranny fluid. Where on earth did the soak the fibers in gas come from? The black plates, I would be cautious of removing material. Green or even pink scotch brite pads? Mic them and see how much you are removing. I like the sheet of 1200 or so emery idea, it could point out warped plates easy. Just watch the material removal and surface texture. The coarser, the quicker your mating parts will wear. Does the inner hub have about 12 or more oil holes in it around the circumference? I really like the heavier springs, what the heck, its got a hydraulic clutch. Them plates should never slip! Vintage Bob

 

[Spokes574]

The steel plates are hard, I did use light sand paper and a green scotch pad - lots of them, the inside pattern of the plates tears up the pad and sand paper. It took about 20 min to do the full set. I remeasured them and the sanding did not effect the thickness. So I should be ok when I do use them in the future.

I put the spacer in to add addl clamping force since the bike is used for motocross most of the time and gets clutch abuse. So far the cluth has been flawless. As I mentioned, using the correct oil (15w50 No Energy Saving Seal) with the stock clutch is critical, as I learned the hard way. But all is good now!

Spokes574
Pleasanton, Ca

 

[Patman]

Why in the world would you soak fiber plates in gasoline?! Gas is not a cleaning solvent. If you feel the need get some brake cleaner otherwise soak in the oil you plan to use.

 

[whenfoxforks-ruled]

I always soak the plates in the same tranny fluid, even that is probably not necessary, but the cork, glue and gas? The old sparkplug washer trick is advanced now, to washers? As long as they do not bind the spring. Now I have found a company that makes pairs of stiffer springs. But with a hydraulic clutch, it should not make the pull harder, unless the hydraulic fails? Vintage Bob