Previous Owner Used SJ Oil

[POLEKAT]

My Kat has 2400 miles. I purchased the bike from the original owner this year (where it had 1700 miles) and he gave me 8 quarts of Suzuki oil 10-40 SJ. He said that this was the oil he put in after the motor was broke in.

The clutch started to slip and grab at high rpm shifts the other day . I don't slip the clutch while sitting still or "fan" it while riding. No abuse.

I adjusted the clutch lever freeplay properly, hoping to cure the problem. Still slips.

Reading through ALOT of posts here, I've come to the conclusion that the SJ oil is the wrong type so I went to my local dealer and bought 10-40 JASO-MA Suzuki oil and new filter today.

Question is: do you think the SJ oil could cause the premature slipping? By changing to the JASO-MA, will I regain any clutch grip? Or is the damage done?

[Fingers]

Yes but it will only be flushed out after subsequent oil changes, not right away.

[The CyberPoet]

It really depends on whether the SJ oil he used had the phrase "Energy Conserving" in the API ring. Any JASO-MA rated oil will not have that statement in the API ring.



Although SJ is not appropriate to the Kats in general ("SH+SJ" rated oils can be used), the "Energy Conserving" additives are the real problem and will not come back off the plates with an oil change or multiple oil changes... Unless you know the previous owner personally, odds are you have no clue whether he was also prone to wheelieing or other behavior that involved lots of clutch slip -- and thus no clue if the problem is specific to the oil or to possible clutch glazing by the previous owners' riding.

You can try these possible fixes:
1. Remove the clutch pack and disassemble it. Look for glazing (looks like burnt oil in a frying pan), and if none is found, scrub the friction surfaces with either a very high grit emory cloth and fresh oil, then reinstall -- this will also fix glazing issues normally.
OR
2. Same as above, but using warm water, a stiff nylon brush and dish detergent (then let dry fully for 4 hours in an oven set to 175 - 200 degrees F [whatever minimum setting is], followed by soaking in good oil for another hour or more before reinstalling) -- this will not fix glazing issues normally.
OR
3. With the engine stone cold, adding Gunk brand engine flush into the oil system and then running the bike for five minutes in neutral, followed by dumping the oil (including the oil cooler's content) -- allow the sump at least a full hour to drain, then replacing the oil filter and oil, running it for 10 minutes, then draining the new oil (including the cooler again, and letting the sump drain a full hour again), and then filling it with yet another batch of fresh oil. If you're lucky, this will work for you. No promises though, and it won't fix any glazing issues.

The only known definite fix is replacing the clutch parts.

Cheers,
=-= The CyberPoet

[POLEKAT]

Well I decided to buy EBC CK series clutch discs and a Vesrah Heavy-Duty clutch spring kit from Dennis Kirk today. I figured the fairings will be off this coming weekend for my Ivan jet kit and ignition advance, so I will change out the clutch pack too. I'll try to take pics of the clutch removal/install.

[The CyberPoet]

Well I decided to buy EBC CK series clutch discs and a Vesrah Heavy-Duty clutch spring kit from Dennis Kirk today. I figured the fairings will be off this coming weekend for my Ivan jet kit and ignition advance, so I will change out the clutch pack too. I'll try to take pics of the clutch removal/install.

I can't imagine that the clutch springs will need replacing, given the age/mileage of the bike... BUT before you button it all up, pull on that clutch lever -- you may find that the heavy-duty springs aren't too your liking (esp. if you do much city riding, where you're in and out on the clutch all the time).

Cheers,
=-= The CyberPoet

[POLEKAT]

If I decide that the springs are too stiff can I run half stock, half aftermarket?

[The CyberPoet]

If I decide that the springs are too stiff can I run half stock, half aftermarket?

Not really (they'll fit but won't act right, overstressing the stronger ones and ignoring the weaker ones). Run all of one or the other.

Cheers,
=-= The CyberPoet