Fith gear issue.
 

What are your opinions on using a synthetic oil like mobile 1 15w50 in the first gen 600 to help prevent the gear damage issue. Synthetic is supposed to take almost twice the pressure to be forced out from between two metal objects as regular dino oil. To me that means no metal to metal contact. THUMPTHUMP

Synthetic oil also has greater lubricity which might make clutch slip more likely.

No other harm will come of running synthetic of the right grade though. (In fact there are other benefits such as improved suspension of contaminants and better longevity).

If you decide to try it, please let us know how you get on. It is only that possibility of clutch slip that has stopped me using it here.

There are a lot of synthetic wet clutch oils. Any that are for atv or motorcycles are usually designed for clutches. I've run syns in quite a few bikes and quads, mostly all I run in the winter. I still have yet to buy any clutch plates(fiber or steel).

I got a noisy fifth...arh...had it since I bought it thanks to previous owner putting gear oil in to make it quiet while I test rode it, nice guy. I shop at a Yamaha dealer/service centre and they assure me the recommended oil is the best for it, and shite loads cheaper...

Problem is the recommended oil does not stop the gear from chipping so their recommendation is useless. The idea is to use the synthetic that takes twice the pressure before you have metal to metal contact. The question is.... is that enough? THUMPTHUMP.

I've used synthetic and the clutch slipped after about 2000 miles. Took it out and put in mineral and the problem stopped.


People do say 5th gear problems but I took my engine apart at 45,000 miles and the flanks of 5th were pitted yes (in my view as a metallurgist) there was plenty of life. However, as I was there I put a new 2,3,5 pairing in at £300. I don't worry about 5th and will only look into it when I get metal in the oil. That's a long way off.

I've run synthetic for about 100.000km on my xt600 with no problem.

What brand and weight Jens? THUMPTHUMP

A lot of diferent brands, f.x Castrol and procycle from Louis.eu, and even some W5 ( i think its called that) bought in Lidl.

It's mostly been 5w40 and 10w50.

I changed clutchplates at 126.000km and they were still within spec.

My Xt350 started slipping slightly in top gears after an oilchange, a new set of clutchplates sorted that. I still use fullsynthetic on the little thing.