Clutch slipping. Could it be the engine oil?

[dropdfocus]

First off, I don't have any reference how old or abused the clutch is in my bike. Anyway, about 1,000 miles into my oil change my clutch has started to slip very noticably in 5th & 6th gear once you hit above 5,000ish RPM and at hard thottle. I can wind out 1-3 up to 7,000 it seems w/o any slipping (or at least any I can notice). I am currently using basic conventional Pennzoil 20w50. Now I know you can't use any oils that have synthetic on a wet clutch because it will cause it to slip. Is this the main reason why the local shop insists I use Kawasaki oil because it does not have any added friction modifiers? (and in case you wanted to know, I work at an oil change shop to pay for my toys & habits)

[oldcoldankles]

I've been using Castrol 10W40 Grand Prix motorcycle oil in my KZ550 without any slippage. Did you notice any problem before the oil change?

[dropdfocus]

Not really, but the kid who had it before me doubtfully changed the oil often. I've changed the oil twice now in the last 1,000-1,200 miles to get out any sludge that may have build up in the motor. I was using 10w40, but the engine didn't like that thin of an oil being that it's old & never torn apart. So I switched over to 20w50 instead. The oil pump likes that much better, but I did change out my handle bars recently & I haven't shortened up my clutch cable yet.

[elr658]

Adjust the clutch and cable per factory procedures and use a Motorcycle specific oil.

[Scruffy]

My bike is doing fine on Castrol GTX 20W50 from Wal-mart...does better than the bike spec synthetic stuff I had in it for 800 miles. Yep, 800 miles on synthetic, bleah. Try dropping the weight down to 15W40, bet the problem clears up. 20W50 is about to get way too thick for your bike, you do get winter there, right? Oilis very subjective, two bikes can come off the line one right after the other, and need different oil weight or type. Blame manufacturing tolerances, hand made parts are precise, but too costly for production lines.
-Scruffy

[dropdfocus]

Thanks for the advise. We definitely get winters here! I plan on putting her away in the next 3-4 weeks. Then becomes the winter long tear down & reconstruction back to new (and even better than new!).

Has anyone run Kawi oil with rather noticable results compared to any general off the shelf conventional oil?

[78_KZ750_Cafe]

Thanks for the advise. We definitely get winters here! I plan on putting her away in the next 3-4 weeks. Then becomes the winter long tear down & reconstruction back to new (and even better than new!).

Has anyone run Kawi oil with rather noticable results compared to any general off the shelf conventional oil?

Everyone says they're going to do a winter long teardown/rebuild/mod session.... good luck beating the odds.

[KLACKO]

Avoid 'Energy Conserving' oil. Shell RotellaT is often recommended by people who I have found usually know what they're talking about.

[dropdfocus]

I would have never thought of that as a motorcycle oil. We use it on diesel trucks only at work.

[BigJohn]

I doubt seriously if it is the oil that is causing the slippage. You say you changed the handle bars recently and didn't make any changes to the clutch...there's your problem. Adjust out the clutch as per the book and the slippage will, probably, get better.

Contrary to Scruffy (we just have a difference of opinion, and I do respect his experience and opinions in everthing else, just not oil type and change periods), I DO use 100% synthetic in my scoot. Mobile 1 Gold Cap 15w50. There is no leakage, no slippage and much smoother shifting. BTW, I also run 10,000 miles between oil changes, changing the filter only every 3 to 5 thousand miles. It also runs quieter.

[dropdfocus]

Got it all taken care of fellas!
It was a combo of the clutch cable needing adjusted in & adjusting out the rear brake engagement. I totally forgot I messed with the rear brake at about the same time I did the handle bar swap. So my brake was holding me back. I didn't realize it until I put the bike up on the center stand to wax the chain & the wheel didn't spin as easily as it normally did. So, she's all back to healthy status for now. I can rip through all the gears once again w/o the clutch slipping out.

[Mercury]

big john.... if you change the oil every 10k miles and the filter every 5k miles... well how do u do that?

dont you loose oil when u do the filter? Isnt that messy?
Im asking cause i have no idea

2. The other question i had was... does anybody use mobil 1 motorcycle specific oil? I think its made specially for v tiwn engines.... i got a 2000 vulcan drifter recently only 1500 miles and I want to use a good oil... i want to make the bike last a while.

I only use mobile 1 in my truck but i dont want too many friction modifiers in the bike cause it may make the clutch slip...

thanks in advance... Kenny

[frogy]

Guys

You do not use conventional OIL, BUY Motorcycle OIL ONLY. it does'nt have the same ingredient.
Oils is'nt that expesive.

and change the filter as well, every other change at 2000Ks

Good luck