every drop of oil (or just most of it...)

I know a few people that swear by flushing oil for their cars - I think it goes in, you do a few miles then ditch it and put the genuine stuff in, they reckon it's the dogs for clearing out all the nooks, I could never be bothered with the car - but would it be an ideal for a bike?

Anyone know anything about it?

Scratch that - I did a bit internet research and came up with this -

Q15.I have often heard of bikers using diesel fuel oil in their engines as a flushing agent. After draining the old oil they add a few litres of diesel. They don't really run the engine but turn it over a few times with the starter motor to remove sludge and other impurities,then drain it before filling up with fresh oil. Is this modus operandi recommended?

A. At Caltex, we don't recommend any flushing procedures, for three reasons. First, engine oils have improved so much over the years that the detergent additives can keep the engine spotless from one drain to the next. If someone insists on flushing out the engine, rather do it with the oil that they are going to use next. Second reason is that the thinner product may hang around after the flush and thin down the oil that is added. Lastly, a number of engines have hydraulic lifters/tappets which trap oil in them. If the flushing oil gets into them, it may not come out again, resulting in incorrect valve operation and damage. There may also be an issue with seals not being compatible with the flushing agent.

from -

http://www.400greybike.co.uk/Wksp-Oil.asp

there's lots of other good stuff on this site about oil and bikes

There used to be a train of thought about using flushing oils, Castrol use to sell one called CASTROL FLUSHING OIL, (it does what it says on the tin)

In my humble opinion it is the equivalent of a painter using gunwash to thin paint :P

It is poor quality and cheap enough to waste,

I just get the engine warm before dropping the oil and filter, that way all or most of it comes out.

But as we have an Oil Technician on board i will let him finish this thread :P

Originally Posted by hutchy

I know a few people that swear by flushing oil for their cars - I think it goes in, you do a few miles then ditch it and put the genuine stuff in, they reckon it's the dogs for clearing out all the nooks, I could never be bothered with the car - but would it be an ideal for a bike?

Anyone know anything about it?

Wouldn't bother - modern lubes are so good that a few percent of the previous fill mixed in won't affect performance / protection.

If you're really finicky you'd protect your engine better by shortening the oil change interval a bit, rather than trying to flush out every drop of the old stuff. Better still spend the extra on buying a top notch oil in the first place. At the end of the day if you stick to the recommended oil change interval with good quality stuff it's not going to be an oil related problem that troubles your engine.

Cheers Keith

When I'm changing the oil, with the drain plug out and the oil drained, I crank the engine for a second. At least another 100ml comes out of it.