I know I've screwed up...How bad is it?

On the advice of a buddy that used to be a service tech for a Kaw dealer (In the 80's), I used Castrol GTX oil for my baby's first oil change in a decade...Now,in perusing these fine boards, I have become aware of the whole "friction modifiers/JASO-MA" thing...I definitely have some clutch slippage going on...Have I totally screwed the pooch as far as my clutch is concerned? Will simply draining and replacing filter/oil be sufficient, or am I looking at a new clutch pack? Fiber discs AND steel discs? TO save me some squinting at a lot of fine print, I would be very interested in what brands of oil are commonly used by members for this application...The local tractor supply has a sale going on "Rotella" oil...would this be a good choice? Crossing fingers...Thanx, all!

I run Rotella T6 in all my bikes without any issues. But oil preference, and tires, are a very personal choice and not to be discussed without argument. 50/50 whether you can save the friction discs. I would remove them, clean thoroughly and reinstall with new oil. Not much to lose other than your time. A guy I ride with did the same thing and had to replace all the friction plates, but his were pretty old anyways. Good luck.

Thanx haybus! What would be the procedure for cleaning the clutch discs...An aggressive solvent, such as lacquer thinner? Milder? (VM&P naptha, etc) Any abrasive? (Sandpaper, whetstone,etc) Should I "flush" Castrol residue out of the crankcase with a mild solvent? Will I need to have a replacement gasket on hand for side clutch cover, or does it come off with cover/stay on case? Sorry,I'm a Newb! Thanx, again!

Do you have a Kawasaki Service Manual? If so, I highly recommend you change the oil and filter using JASO-MA certified oil, but before pulling the clutch apart use the instructions in the manual to properly adjust your bike's clutch. You may find that doing that plus putting in the correct oil solves the slipping problem.

If you do not have the manual, you need to get one. Trying to remove, clean, and re-install the clutch pack and clutch cover without referencing the manual will be a mistake. You need the manual for the diagram that shows where to put sealant (you do NOT smear it on the entire clutch cover edge); how to adjust the clutch when you finish re-assembling it; and torque specs for the clutch springs (and you will need a torque wrench calibrated in INCH pounds). Removing and replacing the clutch is not terribly difficult, but doing it without the manual is not a good idea.

The manuals are usually available on eBay, be sure to get the one for your exact year/model as there are differences. Don't bother with Clymers or Haynes, get the Kawasaki manual. Also, read and follow the info in the link below as it will make you life easier as you work on your bike. Ed

kzrider.com/forum/21-tools/532335-budget...ewdriver-tips#532335

Thanx for the response Ed...I THINK I performed the internal clutch lever adjustment over the Winter, but will definitely do again to make sure...Will most assuredly try your suggestions prior to attempting clutch R/R ! I replaced one on my boys' YZ-80, but it's been years! He has an inch/pound torque wrench also...Regarding the manual...Does anyone know of a link to a pdf for this exact model...I have searched far & wide, and have found just about everything BUT 1978 kz-650 b2. Thanx again, all! These boards are an indispensible resource! Side note: I let my 19 y.o. son ride her around the block a few times over the weekend, first time on a street bike. He loved it...next generation boards' member? Dad was a LOT more nervous than son!

If you have access to a Kawasaki KZ650 manual you can use it for the clutch adjustment; that is one of the few things I believe all the KZ650's had in common. There were meaningful differences in their carbs; electrical systems; and some other major systems, so be aware of the fact that you will need the correct manual for much of the work you may perform on the bike. Ed

Have you tried adjusting the clutch first?

What GTX oil did you use?

I would do the clutch adjustment as outlined in the owner's manual.

As for the Shell Rotella, you can use the regular Rotella-T 15W-40 in the white bottle. It's a heavy duty oil marketed for diesel engine use & is fine for motorcycles - it now has the JASO rating. It's usually cheaper than other oils, which is a good thing. The T6 is a synthetic oil, so it probably costs more. Chevron Delo & Valvoline Premium Blue are a couple of other heavy duty oils.

You know, I did something like this once :S ; I changed to some slick oil when I didn't know better. I ran the bike for some miles, probably less than a hundred actually. The clutch slipped some, but when I realized what I did, all I did to fix it was drain the slick oil, and change it with the correct stuff. The clutch slipped for a bit after the oil change, but in no time it was back to normal.

Thanx for the encouragement! Yes, I have tried the external clutch adjustments, I believe that I performed the internal adjustment over the winter, but definitely will do it (again?)to verify...Martin, 20-50, the kind in a plastic bottle! LOL! Do they MAKE different oils? (I did attach a pic of the back of the bottle.) Thanx for the oil brands, BTW! Snapped pic to bring in, get on here, and look up the oil/clutch slippy ingredient thingie...SHO would like to find a correct pdf manual...Thanx again, all!

I used castrol for decades in my 750. Just make sure you use either 10-40 or 20-50 since those don't have the slippery additives. You could add six ounces of seafoam, run it up to full temp and drain it. Do that a couple of times and your clutch problem might fix itself.

If the clutch is "ruined" from the oil, all you need to change is the friction plates the steel plates are not affected by oil. Another thing is always put in new springs when you change the plates.

You MIGHT be able to clean the fr plates if you soaked them in mineral spirits for a while and then washed them out and let them dry. I never tried it but would not use lacquer thinner or acetone.

martin_csr wrote: What GTX oil did you use?

I would do the clutch adjustment as outlined in the owner's manual.

As for the Shell Rotella, you can use the regular Rotella-T 15W-40 in the white bottle. It's a heavy duty oil marketed for diesel engine use & is fine for motorcycles - it now has the JASO rating. It's usually cheaper than other oils, which is a good thing. The T6 is a synthetic oil, so it probably costs more. Chevron Delo & Valvoline Premium Blue are a couple of other heavy duty oils.

I have had some issues with the "new" delo/e. It's "environmentally friendly and it doesn't have the zddp additive that the old blend did, and as such it cost me a cam and a pair of rockers. The new delo is intended for newer vehicles not our old school bikes. Just my .02 Paul