I found out why there was metal in my oil..

1 reply to this topic
  • LJ

Posted October 12, 2006 - 08:19 PM


My bike: '99 yz400f.

Anybody ever have your springs in your clutch basket disentagrate? In the process of pulling my top end apart to put in new piston, rings, timing chain, and tensioner, I discovered some good size pieces of metal stuck to the magnet in my flywheel. Oddly enough, it looked like chunks of spring material or bearing material do to the curved shape of the ships (about 1/8" x 1/4" x .030").

So it was time to find out where all that metal came from. I pulled the right crankcase cover off and found the outside of the clutch basket scoured. I couldn't find where it was rubbing, so I continued with the dissassembly. When I got the clutch basket off, I noticed the springs where beat up pretty bad, and I found the spring that had pieces broken off of it at the end of the coil. Other springs had some bad gauges from banging against the clutch basket.

I'm trying to figure out how this happened. The only thing I can think of is Installed a Rekluse clutch about a year ago. When I first installed it, I didn't have the torsion spring at the clutch arm on the engine case completely disconnected, so it was applying a slight torque to the clutch assembly. Basically, it fried the clutch in less than 6 hours of riding. Perhaps it got so hot and cooked the springs and made them brittle?

Anybody see this before?

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  • grayracer513

Posted October 12, 2006 - 08:59 PM


I have seen it, and it could have had something to do with the heat, but sometimes the springs just get old and fatigue and break up.

The down side is that the only way Yamaha services them is in a complete clutch basket/primary gear assembly, which would not be good news if you wanted to run an aftermarket basket, since you'd need to buy one of each.

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