Motorcycle oil: Car Synth? (1 Viewer)

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e9999

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I've now been told a couple of times by some guys at the local bike shop that the best synthetic oil for bikes is not the same as for cars, that is one should not use car synth in a bike. The rationale being supposedly that the bike puts more stress on the oil cuz of the trans. Very possibly a bunch of poppycock cuz they are selling what is surely gold-infused synth oil for bikes. I'd rather buy M1 at Costco.
And it may only make a minor difference if one at all.
And I may first exhaust my stock of dino oil anyway.

But what say you?
 
This is true, also depends on whether you have a wet or dry clutch as the motor oil is often used for lubrication in this regard and may have the wrong type of friction modifiers etc...and can cause clutch slipping. Definitely stick to manufacture recommended oil. Depending on the type of motor, I would also be careful using synthetic as it has been known to start leaks and not allow rings to seat if used before the motor has run in completely. Change more regularly than you would on a car or truck application.
 
Shell Rotella, not the mileage increasing kind such as friction modifiers.

http://www.advrider.com/forums/showthread.php?t=165074

If you google the question you will find the majority choose Rotella, cheap and readily available. I run it in my GS1000 and it is bored, ported and makes lots of heat and power.
 
FJB is correct. With a wet clutch, the friction modifiers allow the clutch to slip.
IIRC, diesel rated Rotella does not have those modifiers. YMMV so check.
I am about to run out of a large cache of Motul I got from the distributor a few years back so I am in the market for some bike oil too.
One with dry clutch, one with wet clutch.
 
I'm using the Rotella T6 Full Synthetic in my ST1300. Actually helped shifts, smoothing out some of the clunkiness the tranny has. Clutch feel is unchanged. I did a lot of research because I once ruined a clutch with synthetics *Olmo50), and Rotella meets the Janapese Service code required for most wet clutch applications (brain fade so can't be more specific, sorry).
 
Been running AMSOIL in my 07 busa since the initial break in and been really happy with it, over 12K with no clutch issues yet and I can be pretty hard on it at times.
 
Yep ,car oil can seriously damage wet clutches. Any well known brand will be ok. A DR650 will be fine on motorcycle dino oil.
 
14K on my DRZ400s using Castrol 10w-30 with no issues. Same clutch and I do not treat it nicely, rear pads are in great shape, downshift to slow down. I do change it every 3k.
 
Oil has been beaten to death in many forums; but look for "FRICTION MODIFIER" or "FUEL SAVING" or "RESOURCE CONSERVING" on the label. These terms are often clues there are additives that can damage a clutch, and not all clutches are born equal, some can tolerate a little FM and others will gunk up and start slipping right away.

http://www.pqiamerica.com/Labels.htm

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From my ST1300A Manual (JASO spec is important):

Recommended oil: Pro Honda GN4 4-stroke oil or equivalent motorcycle oil
• Viscosity: SAE 10W-30
• Classification: SG or higher. Do not use oils labeled as energy conserving on the circular API service label.
• JASO 4T Service Classification: MA

http://www.oilspecifications.org/jaso.php
 
thanks for the above. Sounds right.

Indeed, I just talked to Mobil cust serv to confirm whether or not Mobil1 for cars can be used in wet clutches. After some confusion (WTH?), the tech finally stated that it's the Moly in the car oils that is NOT present in the motorcycle oils. Makes a lot of sense.

Intuitively, I do feel like a synth would be good for a motorcycle engine, price be damned. These things are running hot and maybe especially air-cooled ones.

Oddly, though, the Suzuki DR650 FSM does not say anything about FM and car oil. It talks about using general 10W40 SE and above, nothing about motorcycle specific oils.


But the little I know of Moly for bullets is that the stuff is very hard to clean so I would not think that contaminating a clutch with it is a good idea.


added: Chevron Delo 400 LE 15W40 DOES contain Moly as well and is NOT recommended for wet clutch engines - per the Chevron Tech support. Bummer.
 
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Moly is not the only friction modifier ... so any label that says "Energy Conserving" is bad stuff for a wet clutch. For example, Lithium is another such friction modifer.
 
yes, that seems to be the case.
From reading the specs, JASO type MA has NO friction modifier. MB does seem to have some. But again, my FSM says nothing about JASO or additives.
 
Early on, I added Olmo 50 into a bike that had no such requirements, either. Suffice it to say it was an expensive oil change.
 
yea, I think I'll go the safe route. No FM.

You would think the Owner's manual or FSM would state that a No-FM oil is required if the clutch would suffer seriously from FM. Or they might have some serious warranty issues to contend with if the clutch would slip after an oil change where the oil meets the FSM requirement and still damages the clutch.
 
decided on Rotella T6. It's not marketed for bikes but is full synth and rated JMA. Doublechecked with Shell tech and it's good to go. Gear shifts are now smoother, whatever that means.
Significantly cheaper than the motorcycle Synths I saw.
 

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