A quote from "Sports Rider": Can synthetic oils cause my clutch to slip?
To answer this in one word: No. Clutch slippage is caused by many things, but the use of synthetic oil alone is usually not the culprit. The truth is that some bikes seem to suffer clutch slippage no matter what oil goes in them, while others run fine with any oil. This is most likely caused by factors other than the oil, such as the spring pressure, age and clutch plate materials. If you have a bike known for clutch problems, you may have to be more selective in your oil choices. Moly is often blamed for clutch slippage, and it can have an effect-but moly alone is not the problem. We wish there was a hard and fast rule to follow, but it is just not that easy. Simply put, you will have to try an oil and evaluate it. If you experience slippage with the new oil, and have not had problems before, it may be the oil. The plates and/or springs could also be worn to the point that they have finally started to slip. Simply change back to the previous oil and see what happens. You can also check the test data in next issue's article to see if that particular oil has a significant amount of moly. If so, try one that does not have as much moly next time.
We talked to Mark Junge, Vesrah's Racing representative, who has won numerous WERA national championships using Vesrah's clutches. He said that in his years of engine work he has yet to see a slipping clutch that could be pinned on synthetic motor oil. Junge felt that nearly every time the clutch was marginal or had worn springs, the new oil just revealed a problem that already existed.
