Clutch slippage gen 1

[Michael C]

Hello all, I'm looking for a little advice/feedback from more experienced Maxers...I have a 2003 with 13k miles. Bike runs great and I care for it well. The issue I'm having is clutch slippage when I'm on the throttle (already in gear) and accelerating. Usually when approaching 6-7k rpm. The clutch seems fine otherwise and never slips in moderate riding. The bike sat before I bought it a year ago. I went through it and changed/flushed ALL fluids and oils. It seems odd to me that the clutch only slips during hard acceleration in the taller gears?? Should I do a complete replacement?? I know the 'double D' mod could solve the issue, but I've heard that can cause issues with the driveline (u- joint etc.) I'm considering replacing all the friction plates; is that the best course??
Any feedback would be appreciated
Best to you'all !!

 

[MaxMidnight]

Does it make any difference if the motor is cold, during warm up or at operating temperature?
When my clutch started to slip it also tended to be in the higher gears at higher revs.
What oil are you using; some report that fully synthetic can be a cause. Semi synthetic doesn't appear to be an issue and some swear by Rotella.

First thing I would do is establish the thickness of the friction plates. The service limit is 3.1 to 2.9mm; minimum thickness is 2.8mm but from my experience slippage can start before this.
At 13K that sounds early to be down to wear but if it has had a hard life who knows?

 

[Michael C]

I'm using Activo (synthetic blend 10w40). I did use Marvel Mystery Oil when I first got the bike and I've heard that can cause issues with clutch slippage. The bike had 8,900 miles on it when I bought it and looked like it was six months old...well cared for. I ran the MMO for 150 miles. Don't know if that contributed?? I guess I'll purchase new friction plates and open her up for inspection. Don't wanna be unprepared if they are worn.

 

[Michael C]

When I first got it I changed the oil, ran it for 150 miles with the MMO, then put fresh oil and have been changing it evey 2,500. Perhaps the synthetic blend is the cause??
My first Max ('98) never had issues with the same oil...

 

[Traumahawk]

The thing that people don't realize is that the gen 1 was designed in the early 80s. The clutch wasn't designed for synthetic oil. Most people on here, myself included, have had great luck with using a Dino oil. Rotella 15-40.....aka T4, really seems to be what the bike likes. Sean will tell you that he has taken apart engines with 100K miles on them, and still having cross hatches in the cylinders, and using T4, which is a diesel oil.

I buy it by the gallon, and use it in all of my gen 1s.

Eric