Automotive oils in a wet clutch

[04SE]

I know the rules say you can not run automotive oils in a wet clutch because of the friction modifiers. However, I have encountered a growing number of people who use some form of 10w30 or 0w30 in 600cc and 1,000cc sport bikes and even ATVs.

Is the whole notion that automotive oils cause clutch slippage real? You read stories about how somebody walked to close to their ATV or motorcycle with a bottle of non JASO-MA oil and the mere presence of the oil in the same garage caused the clutch to slip. Then you read posts where somebody has been running non JASO-MA oil(s) for tens of thousands of miles with no issues.

I can buy and run SRT 15w40 and ST 15w40 all day for $2 to $3 and know it will work for as long as I own the ATV. However, I like to experiment, simply because I can.

I have a wet clutch ATV and a willingness to experiment for the fun of doing it. If it does indeed take the clutch out, whoopie. That is easily remedied. Besides, Honda allows the use of 5w30 and 10w30 in my ATV. The year round recommendation is 10w30 in my air cooled blast furnace.

Opinions? Factual data?

 

[CarbonSteel]

I am about to being using a non JASO-MA oil in my Brute Force (Mobil Super 10W-40), but it is not a wet clutch bike (it is CVT). I am surprised that JASO-MA was specified unless it is for the transmission--will have to wait and see.

I ran PYB in my two Baja 90cc ATVs for 3 or 4 OCs with no issues, so I am not sure if it takes a long time to see any detriment or??

 

[IndyIan]

Originally Posted By: 04SE
I know the rules say you can not run automotive oils in a wet clutch because of the friction modifiers. However, I have encountered a growing number of people who use some form of 10w30 or 0w30 in 600cc and 1,000cc sport bikes and even ATVs.

Is the whole notion that automotive oils cause clutch slippage real? You read stories about how somebody walked to close to their ATV or motorcycle with a bottle of non JASO-MA oil and the mere presence of the oil in the same garage caused the clutch to slip. Then you read posts where somebody has been running non JASO-MA oil(s) for tens of thousands of miles with no issues.

I can buy and run SRT 15w40 and ST 15w40 all day for $2 to $3 and know it will work for as long as I own the ATV. However, I like to experiment, simply because I can.

I have a wet clutch ATV and a willingness to experiment for the fun of doing it. If it does indeed take the clutch out, whoopie. That is easily remedied. Besides, Honda allows the use of 5w30 and 10w30 in my ATV. The year round recommendation is 10w30 in my air cooled blast furnace.

Opinions? Factual data?

In a moment of brain fade I put in Castrol Syntec 5W40 with all the euro car specs, which made the clutch on my old kingquad slip until the oil warmed up. Putting in proper rotella t has made the clutch bite hard again but it also now sticks a bit. Also my Atv dealer has a few horror stories about clutch linings basically dissolving with the wrong oil.
In short I wouldn't bother, just run an oil that's OK for wet clutches.

 

[Chris142]

I've been using automotive oils in wet clutches since 1977 and have never had any clutch slipage or problems.

 

[BusyLittleShop]

Technically speaking a wet clutch in good working order is not about
to slip no matter what oil the owner selects... what is confusing the
issue is the fact that all motorcycle wet clutches will reach a point
in their life and start to slip... have you notice no one complains
about clutch slip when new... but on about the 27K range contaminants
may build up to point where the clutch begins to loose its grip during
WFO (Wide Fooking Open)throttle only... in error the oil is to blame
but technically speaking its really the clutch...


Technically speaking Energy Conserving oil can not defeat a
wet clutch in good working order... whats confusing the issue
is the fact that all motorcycle wet clutches will reach a
point in their life and start to slip... no one complains
about clutch slip when new... but on about the 27K range is
when containments may build up to point where the clutch
begins to loose its grip during WFO (Wide Fooking
Open)throttle only... in error you can blame the oil but its
really the clutch...

I've been using 10/30 Energy Conserving Mobil 1 since 98 in
Mr.RC45 with no clutch slipping due to oil being certified
10% slipperier than non EC oil... and it's a bike with a tall
first gear good for 90mph that's known to incinerate clutch
plates...

Quote SportRider
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".


Quote Mark Junge, Vesrah's Racing representative

"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."

Friction modifiers additives are only a small percent of the total oil
product and help the base oil do things that it otherwise could not...
Additives fall into several basic categories but Moly is the most
often used friction modifier because it has such a high melting
temperature (4730¯ F versus 2795¯ F for iron), it works great as a
high-temperature, high-pressure antiwear agent. Some claim that
because moly is so slick, it can cause clutch slippage... but note
that 6 of the 19 motorcycle oils Sport Rider tested used moly
including the HP4 market by Honda for any of their motorcycles...