They put lubricating spheroids that take the crushing of the gears in the gear box into the oil. Diesel oil has to take the pounding of the main bearing to the crank journals. Maybe not exactly the same but works for many miles. Regular oil will break down in about 300 miles (483km) after the gears crush the crap out of it. The lubricating spheroids in regular oil will not take the beating.

Detergents are just that, detergents. Detergents foam up and should not be used in hydrolic lifter engines as air will not let the lifter pump up. If a lifter is not pumping up due to deposits, than detergent oil may open the holes and let oil in.

These bikes don't have lifters and detergent oil should not be used because foaming oil is not desirable between the cam and the valve shim. Further more, you don't want air in the oil between the rod/main bearings and the journals.

If for some reason anyone uses detergent oil, they should use it for a short period of time and not put a heavy load on the engine when using it.

 

I was told by a mechanic friend years ago not to use the heavier 20/50 oil. He claimed it increased the oil pressure and the pressure increase would cause leaks. Anyone ever hear that?

 

There would be a slight increase in pressure, not enough to cause a leak. In fact, if it is going to leak it will but you can put thicker oil in to slow the leak because the thicker oil has a harder time passing the thin opening.

You can't go to thick as the oil may have a hard time passing into the area between the bearings and journals. Thinner oils are used in modern engines due to the tighter tolerances of today's manufacturing processes.

 

Stefan2


Quote never heard of having to change it twice as much though !
You don't ! Cost of diesel oil here is less than half the price of bike oil, so you can afford to change it more often.This has to be good for the engine.

Diesel oil has long chain molecules, which help with the "crushing" in a bike engine.
Most car oils have short molecular chains, which break down very quickly as has been mentioned. Not good in bikes..........

I'll carry on with my diesel oil, then, hehe
Rotella T synth is the dog's bollocks hehe.

 

Alright guys, thanks for the heads up on diesel oil, that'll go in as soon as I've got time to do it right

 

"Time to replace real soon, soon as i stop riding long enough"

Hi Johnno - you going to do this yourself - or get it done locally?

I've got to do mine sometime ... Maybe we should do a multiple "Job lot".... interested?