Triumphrat

TridentT160

Since the bikes use a dry clutch, can I run sythetic oil (an automotive synthetic like Mobil 1) in the crankcase for longer life? I know synthetic would be too slippery for bikes with wet clutches.

loxx101

You can, yes. However, if you haven't had the gaskets off for a while they will probably leak due to the detergent in the oil breaking up the residue from the old oil. This got synthetic oil a bad name because people had badly maintained bikes...

Many people will dispute this but at the end of the day, synthetic literally means it's the pure form of dinosaur oil built in a lab rather than mined. It basically doesn't have the rubbish in it. There are some arguments about Zinc content and stuff with old bikes but I can't personally find any evidence to support this being an actual fact.

DAVE M

I have heard the opinion, but can't say whether it's correct, that seals currently fitted may not be ok with synthetic oils.

I'd do a bit of research and preferably get the ok from someone who's done it.

TridentT160

Thanks. I hadn't known about these potential negatives from synthetic.

Mr.Pete

"Mobil 1" comes in a lot of different flavours.Some are low-zinc, low-viscosity passenger car oils.
There are 2 Mobil 1 motorcycle oils that I know of.
Mobil 1 V-TWIN 20W50 has enough zinc (ZDDP) to protect your cams and tappets (more than most oils).You will need more cam protection than the average Triumph twin.

If you get oil leakage,you have a gasket problem and any oil would leak.

Old Cafe Racer

Broadly speaking motorcycle oil comes in Jaso ratings, MA & MB
There are also sub ratings of MA & MB :http://www.oilspecifications.org/art...MA_JASO_MB.php

As long as you have a dry clutch either type is fine.
If you develop oil leaks then that just an indication it's time to pull things apart and fit new gaskets anyway, most modern machines run synthetics with nothing but a silicone sealer between the major gasket faces and have no problem.
The seals are no problem, they are the same material as the new stuff.
I run all three of my bikes on full synthetics, the two four strokes with high zinc type.

rambo

My experience with Mobil 1 car oil in my T120 is.Piston siezure which i fixed.followed by main bearing failure of the roller bearing which looked like the rollers had not been turning due to the low friction of the oil.Never had a problem before or since.The only alteration was using Mobil 1 and the problems started at 100 miles.Bear in mind my 34 years experience with running T120s.I use a motorcycle specific synth now or mineral 20/50 and get no problems at all.When i put synth in,i get gasket leaks,then,change the oil to mineral and the leaks are cured.right now,i have Duckhams Q20/50 and an oil tight motor.Next change will see a synth as it helps oil the chain and lower frame.I quite like the oil trail from the pushrod tubes as it makes it look like its bleeding.If i were choosing a synth,the last one i would put in is car Mobil 1 0/40....Mobil 1 20/50 is excellent however

JohnA

Hmm, so which Mobil 1 grade did you use that seemed to cause the damage Rambo? I'm guessing the very low viscosity but your post doesn't make it clear - and the results of getting it wrong sound frightening!

rambo

It was 0/40 car oil.I find its great in my car engine.Only thing i can think is the oil was so slippery,the rollers did not turn.There was no damage anywhere else but the roller bearing.All ball bearing and plain bearings were un marked.
The biggest advantage of the other synths i have used is the easy starting and nice tickover

loxx101

Thing is, bearings aren't designed with a specific oil in mind like that. The bearings we use on our bikes will be used in masses of applications. I'd be stunned if it was due to the oil.

Do you still have the bearing? If so, whack some pics of the outer race and the rollers!

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