Clutch Slipping

J

JakeBoucher

Hey everyone, as some of you know I bought a 77 suzuki gs750 for my first motorcycle.


Today I just received my permit and got the bike registered. Well I was riding the bike hard and in 2 gear if I get on the throttle and get into high rpms (7000) when I shift to third it feels like the clutch slips. The bike revs up with no load for a sec then It will start to grab and be normal again. It does the same thing if I go from 3 to 4 riding hard in high rpms. I have not tried from 4 to 5 because then I'm getting over 85mph, I just got my permit and don't want to loose it! The last time I rode the bike it showed no sign of slipping at all.


Well about 12 days ago I put some marvel mystery oil into the oil. It was ridden for a short time then parked for a week or so. I'm wondering if the marvel mystery oil has some sort of friction modifier that soaked in causing the wet clutch to slip? Or maybe it's just time for new fibers and steels? I have never experienced clutch slip before so I thought I would ask if my assumption is accurate at all.
 
PALMER84ONE

PALMER84ONE

Could be the Mystery oil and it might not. I would dump the gear box oil and put in the recommended. Run it and see if it slips the same, dump and try again. (Oil is cheep). What are the miles on this bike? Do you have any history on repairs it has had? It very well could need new plates etc.
 
PALMER84ONE

PALMER84ONE

JakeBoucher:
It's got 15,XXX and no I don't have any history on the bike. I was thinking dump the oil, then pull the fibers and steels and soak the fibers in lacquer thinner to get any oil out. Then hit the steels with scotchbrite for kicks.
Click to expand...

Thats a bunch of miles if the plates have never been replaced. Once you pull them, you will know what to do. Cheep insurance to not have to would be to dump the oil and refill a couple times. just run it and get it hot between dumps. And only do the filter once between unless its a SS, then do it both times.
 
bobkyle2

bobkyle2

If you pull the plates and decide not to change them... Soak them in ATF for awhile.

Also might want to make sure there is no lag in cable releasing.
 
snowflake

snowflake

PALMER84ONE:
Thats a bunch of miles if the plates have never been replaced. Once you pull them, you will know what to do. Cheep insurance to not have to would be to dump the oil and refill a couple times. just run it and get it hot between dumps. And only do the filter once between unless its a SS, then do it both times.
Click to expand...
I would go with worn out. Marvel Mystery Oil has no moly or other friction modifiers in it.
BlackstoneMarvelMysteryOilReport.jpg


I would skip on adding it anyway, not needed with modern oils.
 
J

JakeBoucher

Well I pulled the clutch apart today and cleaned everything and dried it out. Nothing looked worn to bad. Definitely better than my 93 rm250 lol. Put the plates back in and poured some wet clutch safe oil over it and spun the inner hub. It for sure felt like it grabbed more than before. I'm waiting on a gasket and I'll let everyone know the results. If it doesn't fix it I guess I'm buying a fiber kit.
 
J

JakeBoucher

Got my gasket today and put everything back together. Don't have any slipping at all, ran great. I did notice something though, on the top of the motor there is a breather that hooks to the airbox. The breather was unhooked from the motor, and the bike has been washed 1 or 2 good times. Could have gotten water in the oil too, didn't look milky when I drained the oil though. Maybe that was part of my problem?
 
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