Burned up clutch?

[CaptainKnobby]

Today There was a race at Iron City MX and boy was it ever muddy. It was so muddy that it was just like soup and the track was standing full of water.

We just raced one moto because of the track conditions and I ran two classes. On my First moto of the second class I didnt make it around the first lap.

The reason why was>>>> Half way around the track on a up hill section the bike was going fine. As I approached near the top I thought I just went into neutral and the bike stoped It wouldnt move at all.

I then thought the chain had came off so I looked and it was still on. I then noticed when I gave it some gas it would nudge a little (not much just a little)

My 06 450 yami was running fine it just would not move. I put a clutch basket and plates and inner hub in it a year ago but I wouldnt think it would have burt up already would it? One other thing I noticed was that the lever was real tight and hard to pull back almost like if you turned the adjuster out to much.

If my clutch is burnt up what parts do you think went bad? so I can order some this week.

Thanks!

[KJ790]

That doesn't really sound like a burnt up clutch since it went from fine to nothing in a snap. Normally a burning out clutch is a little more gradual. Possibly there is something broken in there, or something is jammed. I would pull it apart and see what it looks like inside. Measure all of the plates and check for thickness and warping. If anything is out of spec then replace it.

[642MX]

Sounds like the clutch spun. Time for some new fibers, metals & springs.

[motomanmike26]

I don't think you burnt it up yet like KJ said its gradual. Check everything out. Another tip for keeping the clutch life longer that i learned is to put the side of a penny/dime in between the lever an the perch an tighten it so its snug. This adds extra life to the clutch. ?

[mikedabike]

It is very easy to smoke a clutch in those conditions. All it take is for the cable to start binding and not letting the clutch fully engage. Mud is evil. I did it myself on my two stroke a few years back.

[motomanmike26]

Does it run now? What bike was this on? Yamaha or Honda or whatever your on probably makes an OEM clutch kit for around 100-200$.

[nickeenoo]

I had a mud race on saturday with several river crossings and my clutch did the exact same thing. I just pulled it apart tonight and the nut had spun loose by just a few threads. Not sure if this was the problem but i'm sure it wasn't good.

[CaptainKnobby]

Sorry to be so long to get back. I live at two different places and this is where my computer is.

In the morning I will wash the bike good and pull the cover off to look at the clutch and see what is going on.

I will let every one know and if I have to I will take a few pics.

thanks for the replies and giving me some kind of idea:thumbsup:

[kamaral26]

same happened to me but not in the mud i was just doing a hill climb....sounds like the clutch spun...thats what mine did. replaced the fibers, metals, and springs and was perfect

[CaptainKnobby]

I took the clutch apart today and checked everything and found that the friction plates were out of spec. Some were out as much as 1 mm in some places.

The clutch plates had warpage and the springs were not plum out of spec but had almost reached their free length spec.

The basket and inner hub looked fine(I put them in new about 15 hours or so ago). They had some finger marks on them but they were not cut into the flanges enough to worry about.

The clutch plates and friction plates stunk really bad(you could tell by the smell they had got hot and burnt).

So I guess I will just get the springs and plates and should be ok.

I thought I had put new plates in when I got the basket and hub but I hadnt.

Hard to believe that just the plates burning up like that would cause the bike to not move at all like that but I guess it did.

What all can I do in the future to prevent this from happening again? I try to not use the clutch much but when I come to turns I always have to pull the clutch in.

I guess I will just have to learn to let off the gas sooner and not pull the clutch in.

BTW the pressure plate looked ok too. How would you tell if you needed a new one?

[grayracer513]

This kind of thing happens when the clutch wears enough to eliminate all of the free travel at the lever. At this point, the pressure applied by the pressure plate bears on the pushrod, and not on the plates. After that, it's pretty much all over in a heartbeat if you don't catch it slipping soon enough.

[642MX]

I took the clutch apart today and checked everything and found that the friction plates were out of spec. Some were out as much as 1 mm in some places.

The clutch plates had warpage and the springs were not plum out of spec but had almost reached their free length spec.

The clutch plates and friction plates stunk really bad(you could tell by the smell they had got hot and burnt).

This what I thought you'd find.

What all can I do in the future to prevent this from happening again?

When I had a standard clutch (have a Rekluse now), I used to replace my clutch springs a couple times a year. The springs get weak and the pack doesn't have the correct clamping force. When you replace the springs (before it smokes the plates), you'll be able to feel the clutch grab harder. Might be something to think about...

[CaptainKnobby]

Thanks for the advice:thumbsup: I noticed in my logbook that the basket and hub went bad at 60.1 hours before I replaced them.

I have 81.6 hours on the bike now and the clutch and friction plates and springs are just now being replaced.

I have ordered them already and should be getting them in by next week sometime.

Again! thanks for the help ?

[CaptainKnobby]

I have my parts now which are the clutch and friction plates and the springs and I was just wondering if they have been soaking in oil long enough.

I put the plates in an icecream pale last night at about 9pm and poured a quart of Amsoil MCF 10w40 on them.

If it has been long enough I will go ahead and put them in.

[KJ790]

I have my parts now which are the clutch and friction plates and the springs and I was just wondering if they have been soaking in oil long enough.

I put the plates in an icecream pale last night at about 9pm and poured a quart of Amsoil MCF 10w40 on them.

If it has been long enough I will go ahead and put them in.

Yeah, 12 hours should be fine.

[642MX]

I have my parts now which are the clutch and friction plates and the springs and I was just wondering if they have been soaking in oil long enough.

I put the plates in an icecream pale last night at about 9pm and poured a quart of Amsoil MCF 10w40 on them.

If it has been long enough I will go ahead and put them in.

Actually 30 minutes is plenty of time to let them soak. Some manufactures (like Barnett) recommend less time than that, but I always let them soak 30 minutes just to be on the safe side. ?

[CaptainKnobby]

Well They soaked for over 12 hours. I have them all in now and everything is back together.

I need to adjust the lever now and I was wondering if I could use the thickness of a quarter between the perch and lever.

Looks like to me you would need at least the thickness of three quarters to be able to have ample slack.