Thumper oil?

[Woodman]

thats why your clutch was slipping
you will find in the manual the visc range for the tempertures used

No, it was the viscosity, i don't really agree with the "must use bike oil in bikes" theory, but oil threads never end well.

Sorry, I assumed you were looking for advice over and above the manuf spec.

I don't know, but I'd try a 10W30 or a 10W40 4T motorcycle oil. I would not be using a 15W40.

Too thick a oil is much worse than too thin.


Steve

True to a point. where the clutch is concerned thicker oil can cause slippage, but if you are riding pretty hard a thicker oil gives more protection than a thin oil.

[CookMySock]

if you are riding pretty hard a thicker oil gives more protection than a thin oil.

In the larger bearings yes, but a thicker oil travels more slowly in smaller oil galleries, and places like piston rings and skirts will under-lubricate with a thicker oil. Ring grooves will jam up from lack of flushing.

Steve

[Woodman]

In the larger bearings yes, but a thicker oil travels more slowly in smaller oil galleries, and places like piston rings and skirts will under-lubricate with a thicker oil. Ring grooves will jam up from lack of flushing.

Steve

Yes you are right, how stupid of me. the ring grooves are full of oil so thicker oil will not flush out of the ring grooves, and if the engine is running harder the oil will not run hotter therefore a higher viscosity oli will will not be thicker than a lower viscosity oil at the same temperature therefore offering better protection.


FFS

[warewolf]

Arrrgghhh! an oil thread. :slap:

I've never had a problem with any bike running the manufacturer's spec oil (not necessarily spec brand). The only issue with car oils is due to the wet clutch; you must avoid oils with "friction modifiers" or whatever. Wikipedia has some useful articles: Motorcycle Oil, motor Oil.

btw Motul 5100 is only a semi-synth oil. I used to run it (and more so, its predecessor 3100), but it coated the engine with a yellow gunk. Dunno if that was harmful.

Lots of oil threads in the off-road forum. Some folks only ever run diesel oil in the engine and ATF in the forks. Whatever lights your fire, I guess.

[NordieBoy]

Some folks only ever run diesel oil in the engine and ATF in the forks. Whatever lights your fire, I guess.

I use one of those little gas match things.