I've always ran full synthetic in my other bikes, since getting an FJ (which is not running...working on that), I came across a few people saying to use conventional to avoid problems with starter or clutch. What are you running?
Also, what viscocity are you running? 10w-40?
Warning!!! Oil thread....
Many will tell you to pick one (Dino/Syn) and adjust viscosity to taste. I found the starter clutch has a harder time in the cold with thicker oil. Not the oil's fault, the starter clutch is known to wear out. Keep it clean and topped off.
Thanks, I did look around and didn't see any other posts so figured I'd give it a shot. I'll start with 10w-40 syn and adjust if needed.
Make sure it's motorcycle oil that's safe for wet clutches.
Automotive oil will cause your clutch to slip...guaranteed.
thank you and yes def motorcycle oil
Here is an interesting piece on oil. https://www.youtube.com/watch?v=8XtLDdaFDNA&t=310s&pp=ygUPQ1lDTEUgV09STEQgT0lM
That was interesting thanks
My opinion and advice on oil for motorcycles is this.
The engine does not care what Brand or type (conventional/synthetic) is used. The engine cares that there is an adequate amount, the correct viscosity for your temprate zone, and that the oil has the JASO MA or JASO MA2 rating. Beyond that, everything is Smoke and Mirrors on which is best.
Fred
Fred
Mineral Bel Rey is perfect.
I changed to synthetic oil in the FJ mainly due to it handles the heat better when traveling longer distances. Yamalube syn was a good value. 10w40
Quote from: moparman70 on December 04, 2025, 11:39:57 AMI changed to synthetic oil in the FJ mainly due to it handles the heat better when traveling longer distances. Yamalube syn was a good value. 10w40
Yes, I have also found that to be true.
An ester stock synthetic does not burn off on long rides, especially when crossing the toasty Arizona desert in summer.
I tend to run Morris Oils Versimax HD3 mineral oil, 20w-50. It's sold as an oil for diesel engines, but has been recommended and used by the FJOC here for over 3 decades (it was previously called Ringfree).
My experience of synthetic oil in my first FJ was not good. I used motorcycle specific Silkolene 10w-40 fully synthetic oil and within 50 miles my clutch started to slip under acceleration.
Fixing the oil and going back to 20w-50 mineral oil didn't help. I had to put in new clutch plates.
Ever since then resisted the temptation to go for "better" synthetic oil.
My current FJ has never had anything but mineral oil (Morris, or Yamalube 20w-50) in it and at 107,000 miles has never had any issues with clutch slip, or anything sense related to oil.
I'll just stick with what I know works.
I have always used synthetic JASO oil. Mannol 15W40 fir instance
I've not had good luck with synthetics in my FJ, and that may just be me.
I'm going to change the oil every 2000 miles anyone, good old fashioned mineral oil is fine IMHO.
Rotella was the most disappointing, as it seemed to not shift as well as others.
Quote from: FJ1200W on January 01, 2026, 08:27:34 AMI've not had good luck with synthetics in my FJ, and that may just be me.
I'm going to change the oil every 2000 miles anyone, good old fashioned mineral oil is fine IMHO.
Rotella was the most disappointing, as it seemed to not shift as well as others.
I've not had good luck with fully synthetic oil either in my earlier FJ, clutch slip within 50 miles of the oil change.
Had to replace all the clutch plates and fill with mineral oil to stop it slipping again. Never tried Synthetic again after that experience.
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.
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.