Can anyone speculate or has anyone had this trouble?

Mine is a 99. I just recently overhauled the engine and if the bike sits for a week or two and then started, it blows blue smoke indicating that it is buring oil, but this clears up and stops within 1 to 2 minutes after start up. Also, when I check the oil when the engine is cold (or has not run in a few days), the oil tank is empty. When I take it out and run it a good 10 miles and then re-check the oil, the level is correct.

It appears as though the oil is draining back down to the engine but I am not fully sure. These bikes hold about 5 liters of oil in total and if it drains back to the engine, my guess is that the engine is so flooded in oil that the lower cylinders are immersed in oil causing some of the oil to be displaced to the combustion chamber untill the oil pump can pump it back to the tank.

Its only my guess but I was wondering if anyone else has seen this before?

Since the overhaul, the only thing that has been changed in the oil system was the oil filter which lead me to wonder if there might be some kind of a one-way (check valve) in the oil filter causing the oil to seep back to the engine's sump.

All opinions welcome!!

Thanks...Andrew

Andrew,

This is normal in some R*'s. There is a check valve, but it's in the oil pump. We actually have a 'semi'-dry, pressurized, oil system. Over time the oil seeps past the check valve of the oil pump and most of the oil is as you've figured out. It goes into the crankcase.

Just a quick starting and the scavenger side of the oil pump puts the correct amount back into the oil tank. This is normal with some engines and is not a thing to loose sleep over, (my opinion). My 01 does the same thing and I've got over 40,000 miles on it with no oil lose or problems.

Hope this helps,

Odo

Odo,

Thanks for the post. Mine had never done it before this and the only that was changed in the oil system was the filter. I used to use only the yamalube 10w30 when i lived in canada but now i live in Dubai and the temperatures here warrent the 20w40. This time I ended up having equal parts of both viscosities on hand and ended up with a 15w35. Its about time to change the oil since the overhaul so maybe a new oil and filter may help. i had started to speculate that there may be a touch too much oil in the engine total so this time I will measure the amount going into the engine instead of only using the dipstick. I would think that getting to the oil pump requires splitting the engine and I dont cherish that thought.

Thanks again....Andrew