Exploding Clutch

Message

m00cher · #1 Post by **m00cher** » Mon Aug 18, 2008 8:40 pm

Has anyone had this happen to them?

Just hit the power band in 1st gear then "BANG"

Can you re-weld the studs onto the inner clutch basket, or is this not advised because of possible Strength or balance problems?

Karl

gus · #2 Post by **gus** » Mon Aug 18, 2008 10:03 pm

yes and no, never on a 500 but on a yz, I think what happens is people pry on the studs that hold down the clutch springs they crack but are strong enough to not break YET! a few pulls on the lever and then off the stud comes jams into the cover and the rpm of the motor overcomes the bind and pops the cover open, ouch, how many broke there doesn't seem to be many left, what we did was countersink the other side run a tap all the way through use a flat head screw, some loctite they never come off then.

#3 Post by **smurph** » Tue Aug 19, 2008 1:05 am

Awe man, that left a mark. I hate to see stuff like this.

#4 Post by **hybrid** » Tue Aug 19, 2008 1:06 am

On the plus side, you could fit a nice clear insert now

YPVS KIWI · #5 Post by **YPVS KIWI** » Tue Aug 19, 2008 7:18 am

Ouch !! that gotta hurt.

Will be taking special interest in the condition of screws and threads in the hub when I re-assemble mine.

Guillaume · #6 Post by **Guillaume** » Tue Aug 19, 2008 7:55 am

m00cher · #7 Post by **m00cher** » Tue Aug 19, 2008 11:49 pm

None of the studs survived. Did manage to find most of the bits after abit of running backwards and forwards accross the road where it happened.
Surprisingly the the Yamaha cover hardly got a mark on it after flying onto the wrong side of the road.
I think that doing the clear clutch cover is now on the cards.

YPVS KIWI · #8 Post by **YPVS KIWI** » Wed Aug 20, 2008 1:57 am

Did it break the studs or pull the threads out of the hub ?.

m00cher · #9 Post by **m00cher** » Wed Aug 20, 2008 11:10 pm

All the studs broke.
Bad news, both clutch cover and inner clutch hub are NLA.
Good news local engineer said he could fix the cover and i've got a spare clutch basket.

Smoker · #10 Post by **Smoker** » Thu Aug 21, 2008 1:30 am

What caused this?

[Just trying to learn.]

#11 Post by **smurph** » Thu Aug 21, 2008 1:52 pm

Someone probably used the studs as a leverage point when removing the drive nut. There is a special tool for this that many don't have in their back pocket. The studs might break during the nut removal but sometimes they just crack, leaving them to survive to do damage like this.

This is the primary cause, but the hub could have also had a rough life. It could have been dropped. Or it could have just been a manufacturing defect that just showed up.

Steve

m00cher · #12 Post by **m00cher** » Thu Aug 21, 2008 3:21 pm

I'm guessing thats whats happened from one of my bike previous owners as I used a rattle gun to do up clutch nut. One of the reasons I got 1 as i could work out how to hold it.
Getting someone to tap the treads all the way through on the replacement basket with longer bolts I'm going to use as it looks a bit worn and not keen on a repeat.
The motor had been together for at least 4 year and had done a fair few km's in that time and I'm not really a person who takes it easy like when it happened taking off from the traffic lights.