HELP!! Clutch burning on KTM 350XC-F

[MXA622]

Okay so first of all right off the bat obviously my clutch keeps burning. BUT! Before you go off and ask me if I’m doing things right.. Keep noted I’ve been racing my entire life and am a Double A offroad-racer going through training coaches and professionals even who have won gncc’s i can assure you I’m doing everything right and riding the bike as i should. Secondly manually slipping the clutch is an absolutely normal thing is actually a must have for racing, i slip the clutch a lot but knowing my boundaries by how much i should slip my clutch, and how aggressively. I know when my clutch is slipping, when something’s wrong, or when I shouldn’t be slipping the clutch. I’m using Ams-oil 4T engine oil. And after my stock plates burned a while back i put on tusk plates. Although having tried Pro-X with the same result. The only time even very rarely my clutch stands a chance at burning would be on a major hill-climb, but even then it’s not enough slippage to fry the clutch! I’m getting a fried clutch every &%$#@!ing 35 - 40 hours and im pissed it’s too much money. I’m not sure if there’s any air in the clutch line/lever. I’ve only got 220 hours on the bike so i’d have to give it a look although doubted. People often talk about plates being blue or warped. Mine are just straight up &%$#@!ing black. Im trying to give you as much information as i can but I don’t even know what could be the reason. The bike should be able to handle my abuse, that’s what’s triggering because if you’re gonna make a race bike it better be able to handle a racer and it doesn’t quite seem like it can. Is there any other reason why i’m having these issues? Ask away, i’m glad to answer. Here’s some pictures. HOWEVER!! One thing to note, i am using a midwest engineering clutch lever BUT i tune it every single race to make sure it doesn’t fry the clutch. The midwest lever makes it easier to pull the clutch in, Ive got some tighter springs on my clutch to keep it from getting fried. 

[mog]

Some riders do fry clutches at 40 hours 

 

Have you had other bikes last longer?

[WALKINGWOUNDED]

Does his bike have springs, or a Belleville washer?

Maybe it has lost it's tension.

[Hans Schmid]

When I sold my 19 350, when doing a clutch fluid change a bit of debris got in the line. The new owner burnt 2 clutches before he discovered the problem... The clutch would feel engaged and worked until it got super hot, eventually failing... 

[MXA622]

16 hours ago, mog said:

Some riders do fry clutches at 40 hours 

 

Have you had other bikes last longer?

I just expected it to last a bit longer for anyone really. I’m 15 so I haven’t had a life’s experience with these mechanics. My dads the one that’s gotta pay for the clutches. I was thinking a rekluse manual clutch might last longer i have no clue.

[mog]

You didn't say how long other bikes lasted ?

[MXA622]

48 minutes ago, mog said:

You didn't say how long other bikes lasted ?

That’s the tricky question, I haven’t had many other bikes it’s a 2017 no dds clutch. The only other bike i’ve had was a 2012 KTM 350XC-F and no it didn’t fry the clutch as much but I wasn’t as good back then either. Just recently I’ve shot up in skill and into double a. So it’s likely to be my riding. I also happen to find a lot of people with the same problem on the 350.  I highly doubt it’s the bike though as most people with 350’s are in my skill level and above. So yeah i guess it’s just my riding but i hate the cost and having to replace it’s outrageous. Do you have any tips any better plates, or oil to use? I’m using amsoil atm wondering if Maxima might be better. But then again amsoil is like #1.

[MXA622]

16 hours ago, WALKINGWOUNDED said:

Does his bike have springs, or a Belleville washer?

Maybe it has lost it's tension.

Clutch plate springs? Yeah it’s got aftermarket springs they’re a bit tighter than stock to try to reduce some friction. Which is what everybody’s saying. No clue what a Belleville washer is. 

[MXA622]

15 hours ago, Hans Schmid said:

When I sold my 19 350, when doing a clutch fluid change a bit of debris got in the line. The new owner burnt 2 clutches before he discovered the problem... The clutch would feel engaged and worked until it got super hot, eventually failing... 

See here’s the thing, not sure if you’ve ever heard of a Midwest engineering lever. But i love them because they mechanically reduce the force needed to pull the clutch in. And it’s fabulous with arm pump! But it’s known to burn the clutch if you don’t set it right. However i set it every race and it’s not slipping. I’m getting full power no slippage. I’ve also been told that the clutch plates aren’t supposed to turn black which refers to the oil burning on the plates meaning that’s an oil problem. So i might try changing oil as it’s an affordable option. Using amsoil atm.

[Hans Schmid]

4 minutes ago, Max Arey said:

See here’s the thing, not sure if you’ve ever heard of a Midwest engineering lever. But i love them because they mechanically reduce the force needed to pull the clutch in. And it’s fabulous with arm pump! But it’s known to burn the clutch if you don’t set it right. However i set it every race and it’s not slipping. I’m getting full power no slippage. I’ve also been told that the clutch plates aren’t supposed to turn black which refers to the oil burning on the plates meaning that’s an oil problem. So i might try changing oil as it’s an affordable option. Using amsoil atm.

Deductive logic would tell me to go back to stock levers first and try those.. 

[mog]

If your using the Midwest lever on a 350 I guess you are slipping it too much 

[MXA622]

9 minutes ago, mog said:

If your using the Midwest lever on a 350 I guess you are slipping it too much 

Okay maybe stock springs and a regular clutch lever? Cause I absolutely cannot stand the stock shit it’s way too hard to pull in. It’s like it’s made for riders who never use their clutch. I’m never not using my clutch but on straightaways. The stock one gave me LOADS of arm pump. It’s not that it’s too hard to pull in because i can pull it in easily. It’s just for a long duration of time pulling it in consistently it puts wear on your forearms. Any suggestions?

[ktm400rcer]

You stated you're using Amsoil 4t. That's meant for Briggs and Stratton kart engines. As a Amsoil dealer since 1982, I suggest 10w-60 dirtbike oil. Both the 10w-50 and the 10w-60 are recommended. The 4t is NOT recommended and may be the root cause of your issue. The stronger springs should help prevent burning unless they aren't releasing completely. I am not familiar with your lever setup so I can't make any recommendation there. Good Luck.

[Ud_Luz]

Take a look at your master cylinder. You probably have a 10.5mm. Replace it with a 9mm. This will reduce clutch pull greatly helping with arm pump. Keep in mind it may make finding neutral a bit more difficult.  You are in fact slipping the clutch and burning the oil and plates. Apparently your training coaches and professionals haven't really been addressing clutch control with you. Frankly if you are a AA racer running in races with tighter woods and such I wouldn't be too surprised you're going through clutches. The KTM clutch is a pretty solid unit.

Rekluse has a manual clutch that's slightly better but it isn't going to help you much. Learn clutch control or get a 500, most mortals don't need to slip the clutch on the 500. ? 

[Hans Schmid]

3 hours ago, Max Arey said:

Okay maybe stock springs and a regular clutch lever? Cause I absolutely cannot stand the stock shit it’s way too hard to pull in. It’s like it’s made for riders who never use their clutch. I’m never not using my clutch but on straightaways. The stock one gave me LOADS of arm pump. It’s not that it’s too hard to pull in because i can pull it in easily. It’s just for a long duration of time pulling it in consistently it puts wear on your forearms. Any suggestions?

Change only ONE thing and see if that works. 

[Russell Dp]

3 hours ago, Max Arey said:

Any suggestions?

Sounds to me like your exceeding the capabilities of your machine... I mean, congratulations on being only 15 and smoking the living shit out of your clutch to wring more power out of your bike and all but maybe it's time for more horsepower from a bigger engine?

[AvB]

The MWME lever just increases the mechanical advantage so for the same amount of clutch lever pull, you get less movement of the slave piston. This reduces force required,  so it's counterproductive to then go and make the clutch springs heavier. 

When your bike warms up, and the plates swell a bit with heat and fluids get hot, it reduces the clutch lever free play. That's accentuated quite a lot with the MWME levers. So if you set your lever action when the clutch is cold, it can start to take up and even slip when it gets really hot. Some systems are worse than others. For ages I must have had a tiny bubble in mine and it was crazy, I'd set the lever and after half an hour of hard gnarly clutch-slipping hill stuff, it would get so tight it would start to slip.  Drove me nuts. I bled it about 5 times and one day I bled it back and forth from both top and bottom and suddenly pop, a tiny tiny bubble came up, and it's been good since. But it still does "tighten up" as it gets hotter. Maybe that's not your issue but worth mentioning. 

Edited October 23, 2020 by AvB

[ROWEBOT3339]

Dude, you don't know jack about thermodynamics, that's your problem.

You have a ~50hp engine dumping heat into a place it's not supposed to produce much heat. The transmission.

The clutch is not meant to be ridden constantly at high rpm and WOT. Too much heat going into that oil. There is no cooling down there but convection and conduction through the casings. The oil cannot hold much heat. You are boiling the oil, which is trashing your components.

Your best bet is find the best oil with highest flash point and best shear resistance. 

[mog]

You should not be using the clutch much on a 350 honestly

[Big Dan th donut man]

2014 350 xcfw 6 days 120 hours. 3rd clutch replacement.  After 3 weeks in the shop and a lot of thrown wrenches, they are telling me its the main shaft bearings. Under load it has the appearance of a slipping clutch. Ill update when I find out for sure.