I bought my bike used with 5,000 miles on it and have driven it about 4,000 miles so far. I changed the fluids and used Mobil 1 V-Twin synthetic 20w50 a few hundred miles ago. I just noticed it is slipping under load in higher gears like 5th and 6th. I thought that this may be fluid related but thought I would try and adjust my clutch again to see if it helps. When i had the cover off, I noticed that my diaphragm spring has a yellow stripe on it. Is this the correct spring for a 103 engine? I was reading that the SE spring may be the way to go? I'll be ok with a heavier clutch lever. The only mods I have done are slip ons.

 

Have you varified that the adjuster hex and locknut are perfect?

 

Well from here, the nut looks like it's trashed..

And loose..

 

I agree, the nut looks bad. It was already like that. I think I'll get a new nut and spring at the dealer and see how it feels. I can always put the stock spring back on.

 

Don't go to the dealer to get the nut, get a standard nut from an out parts place.. It eill be taller... 7/16-20 national fine.. So what bike and how many miles? any mods? You might want to replace the clutch frictions wile you are at it.

 

So, I replaced the clutch diaphragm spring (SE spring) and added new Formula + oil in the primary. I adjusted the clutch per the service manual and the clutch still slips a bit. I took a test ride and it shifts up and down fine but when I get on the throttle a little hard, the tach jumps up about 500 rpm's and then it catches. It reminds me of a snowmobile clutch.

Looking at the service manual again, I guess I should have taken taken the friction plates off and inspected them, I know that was also suggested here. Is it really simple to just pull the plates off? And if they're bad, can I just buy the friction plates? It looks like they're are 10 of them?

This may also be helpful, I was running Mobil 1 20w50 synthetic in the primary for a few hundred miles. It is possible that the synthetic oil is still on the clutch and causing it to slip?

Lastly, would it hurt the clutch anymore riding it this way until I fix it properly? The bike has just over 9,000 miles, I can't believe the clutch would be bad yet.

 

The stock plate count clutch has 9 plates. You would be better off going aftermarket frictions.. I'd use Barnett stock plate count Kevlar.. Others will have their favorites. As long as you don't let it slip too much you'll be OK.. If you let it slip a lot, you could warp the steels and possibly damage the pressure plate / clutch hub.. You could try to rough up the steels with some sand paper or a bead blaster. That typically helps.. Some of the issue might have been the synthetic motor oil.

 

Well, I think I found the problem with my slipping clutch. I adjusted it one final time and it still slipped. I took the primary off (I'm getting fast at that now) and took the clutch pack out. The manual states that if they measure less than 0.143 in. that they're bad. Mine measured at .0945 in. Yikes...No type of clutch adjustment would fix that. I'm calling the dealer to get a price on a stock clutch pack since I don't have any engine upgrades. I still may go with the Barnett though.

 

I got it fixed. The specs weren't as bad as I thought because I forgot to zero out my caliper, duh. They still measured lower at .140 though. I went to my local indy and bought a Barnett clutch kit and got it all put together with new fluid in about an hour. It rides great now.

 

Wow, how does a clutch pack wear that much in 5K miles??? When I replaced Reaper's original clutch pack with a Barnett extra plate kit, a few years ago, the frictions looked almost new, and they had over 80,000 miles on them!!

Cheers!