Slipping Clutch

[Brian Donofrio]

My clutch is slipping usually above 55 MPH. I have checked the springs length and they are off a tiny bit. My 4 clutch bolts are properly torqued and the adjuster is set giving the clutch rod some clearance.

I am using 10 w 30 full synthetic motor oil. It's winter here in New York need light oil.

The fiber plates and steel plates look good and are properly installed.

Anybody here ever have clutch slip problems?

I'm just trying to cover all the basis before I start changing out parts.

Thanks,

[primal]

10W-30 probably has friction modifiers that cause the clutch to slip. Check the API donut on the back of the oil bottle and see if it says "Energy Conserving." If it does, that's your culprit. Your best bet would be to get a 5W-40 oil (the first number is the most critical for cold weather) that lacks friction modifiers. Shell Rotella-T 5W-40 synthetic oil is popular.

[patrick_777]

+1 for Rotella-T. I use it in both my bikes. Most of the sport crowd around me even use it on the track, so it can take a lot of punishment.

...and about $3.50 a quart doesn't hurt either.

[Badbob]

Originally Posted by Brian Donofrio

My clutch is slipping usually above 55 MPH. I have checked the springs length and they are off a tiny bit. My 4 clutch bolts are properly torqued and the adjuster is set giving the clutch rod some clearance.

I am using 10 w 30 full synthetic motor oil. It's winter here in New York need light oil.

The fiber plates and steel plates look good and are properly installed.

Anybody here ever have clutch slip problems?

I'm just trying to cover all the basis before I start changing out parts.

Does the slipping mostly happen on hills?
Does it happen under hard acceleration?

Clutches can wear smooth from using the clutch a lot. Apparently this happens a lot on dirt bikes. There are a couple of fixes you can try.

Check this out before you get all bent out of shape about your oil.
viewtopic.php?f=8&t=1568

It worked for me.

Also check that your clutch plates are flat.

My wifes GZ250 has Mobil1 (Gold Cap) complete with friction modifiers and has been using it for nearly 6,000 miles. It doesn't slip at all. Ever.

You might want to give this a look as well:
Obsolete API Oil Ratings

[Easy Rider]

Originally Posted by Badbob

My wifes GZ250 has Mobil1 (Gold Cap) complete with friction modifiers and has been using it for nearly 6,000 miles. It doesn't slip at all. Ever.

SIGH! :skull:

[primal]

Originally Posted by Badbob

My wifes GZ250 has Mobil1 (Gold Cap) complete with friction modifiers and has been using it for nearly 6,000 miles. It doesn't slip at all. Ever.

When you can get a high quality oil in the proper weight without friction modifiers, for cheaper than Mobil1 (I'm assuming), why would you even bother using an oil that puts you at risk of a slippery clutch?

[Badbob]

Originally Posted by primal

When you can get a high quality oil in the proper weight without friction modifiers, for cheaper than Mobil1 (I'm assuming), why would you even bother using an oil that puts you at risk of a slippery clutch?

I had been using this all along and didn't notice that the formula had changed. I don't know that it puts it at risk. What I know is that lots of people claim it does. What I know is that in one GZ250 this oil doesn't make the clutch slip.

[Easy Rider]

Originally Posted by Badbob

What I know is that in one GZ250 this oil doesn't make the clutch slip.

Yet ! :biggrin:

Since this is your wife's bike, is it safe to assume that her riding style is on the conservative side ?? That might be a significant factor.

[Badbob]

Originally Posted by Easy Rider

Since this is your wife's bike, is it safe to assume that her riding style is on the conservative side ?? That might be a significant factor.

I ride it from time to time. I can't make it slip. My daughter rides it on camping trips. No complaints there either.

Mine slipped with any kind of oil. Even dino and motorcycle specific oil.

BTW: I use Mobile1 V-Twin. Why? Because it is available and I got tired of this game.

[Easy Rider]

Originally Posted by Badbob

BTW: I use Mobile1 V-Twin. Why? Because it is available and I got tired of this game.

TA-DA !!

Me too. :biggrin: