I have a 2005 Beta rev3 in pretty good nick with not many hours under its belt--The other week I noticed that the oil in the sight glass was milky in colour so I changed it--Its gone just the same again, can anyone tell me why. Cheers

Are you losing coolant as well? More than likely the water pump seal? Plenty threads on this subject if it is.

GJ

is it white when you drain it out, mine starts of looking milky , then clears and is fine, and works fine.

had you had it running before you looked in the window?

Mine goes milky colour, I think it is the air in the oi from running the engine, If you leave it stood still it should go back to normal colour!

Hope this helps

Because trials are seldom used every day, the engine oil will tend to absorb condensation after a run. Tends to be worse in cold weather and during damp climatic conditions due to a higher moisture content in the atmosphere. A good run up to normal operating temp should evaporate it off. I bet if you check the oil sight glass again after a decent run it has cleared.

Only worry about this if accompanied by white exhaust smoke and/or loss of coolant which would indicate gasket or water pump trouble as mentioned by others on this post.

Oil won't go white from drawing water out of the air when it isn't used. No chance.

As above for water pump oil seal could be faulty.

If the bike was stood in a stream it can draw oil up the engine breather tube if it is hanging low (and in the same water). .... this is a good reason to have the breather tube go up toward the head stock.