Bubbling Oil - Can someone please explain?

For the past couple of weeks when checking my oil through the view glass I've noticed it's full of bubbles. Is it because it's getting too hot?

Bike temp, idle speed, running & general sound etc all seem fine. It's been serviced at all suzuki advised intervals. It's done 14k and will be ready for another service at 14,500 miles.

Should I be worried? Anyone got any ideas? It doesn't seem to be using any oil - Even after a couple of recent trackdays.

Does it look like oil or is it more like a creamy sludge?

The oil will look like its bubbling as its being slopped about quite a bit even at idle rpm.

Could it be because it's slightly too full?

Is it like that after a short run...or a long run? If you are doing lots of short runs, it might have some condensation in it and therefore a bit emulsified?

If youre doing lots of short journeys, your oil with build up water in it - making a creamy looking emulsion. Either change your oil, or go for a long blast to "Boil" the water out. The latter sounds better to me...
Sorry Officer, I was only boiling me oil!!

[jambo]

Oil boils somewhere north of 350 degrees C. Coolant boils off somewhere north of 120 C, if you still have coolant in the bike, the oil isn't boiling.

The only time I've read of oil boiling was when a bike magazine held the throttle open on an F model ZX6R for about 20 minutes, stationary without airflow. They were destruction testing the engine at the time.

What does happen though is it gets nice and warm and runny, and then whisked up by the gears and whirly bits inside the engine, this adds a little layer of bubbles at the top of it, it's not a problem

[G]

Originally Posted by jambo

Oil boils somewhere north of 350 degrees C. Coolant boils off somewhere north of 120 C, if you still have coolant in the bike, the oil isn't boiling.

The only time I've read of oil boiling was when a bike magazine held the throttle open on an F model ZX6R for about 20 minutes, stationary without airflow. They were destruction testing the engine at the time.

What does happen though is it gets nice and warm and runny, and then whisked up by the gears and whirly bits inside the engine, this adds a little layer of bubbles at the top of it, it's not a problem

I remember that test, didnt the oil boil nearly dry, until it clunked out.

They then topped it up with fresh oil and the bike ran fine again?

There is a pdf online somewhere with all the tests they did.

[jambo]

Soulkiss posted this a while back here

thanks all - The oil isn't too full it's just below the full mark. Plus, I don't actually do that many short runs. Usually 70 - 120 miles. You have all got me thinking though. I usually check the oil at the service station round the corner when checking tyres. It's only 1.5 miles away so perhaps I need to check when it's had a bit more time to warm up. The oil (although bubbly) still isn't dirty, in fact it's quite clean. I'll have a look for the Bike article. I've got a few yrs back issues.

Thanks for all your comments.

[Paul the 6th]

sev, mine bubbles when I rev it. I made the mistake of over filling it about 2 months ago, then spent 2 hours figuring out how to drain the excess away. Emptied it out a bit, then topped it back up to the normal level. That was when I noticed "oil bubbles" sat at the top of the oil level. When I rev it, the oil bubbles flicker and multiply/become small. Just like jambo said, when the engine is rev'd the mechanicals and gears pick up oil and slap it all around the engine to keep things nice and slippy.

If it is something serious, I've not had any problems. Where the hell is yorkie chris anyway? 10 posts and he's no where to be seen?! lol

paul w