Synthetic or Conventional Oil?

[Pat Conlon]

Dean, are you running the stock diaphragm clutch spring?

I've never had a clutch slippage problem with motorcycle specific synthetic oil, like Redline, then again, all my FJ's have the Barnett coil spring conversion.

 I've thrown away those weak ass oem clutch springs long ago...along with the airbox, cartridge oil filter, shock, fork springs,  rubber brake lines, front calipers, 16" rims with those bias ply donuts, etc, etc.

[Millietant]

Yes Pat, I'm still running the original diaphragm spring in my main FJ. So far, I've never had a clutch slip issue with this bike over it's 107,000 miles.

It was my first FJ that had the issue, at under 10,000 miles, with the Silkolene Pro 4 Synthetic 10w-40. Once I'd replaced the clutch plates (and kept the diaphragm spring) and gone back to mineral oil, I never had any further problems in the following 38,000 miles.

However, my engines have been basically stock (just air filter and exhaust changes), so my clutch hasn't had to deal with big bore engine torque increases. Having said that though, it's done thousands of track miles as well as many fully laden 2 up tours around the Alpine hairpins without any problems. I'm also someone who doesn't do "drag starts" and I rarely use the clutch once on the move, other than 1st and 2nd gear shifts up/down, so I guess I'm pretty "light" on it.