speaking of 1150GS oil what does this mean

[manybikes]

I changed the oil in my 04 GSA a couple of weeks ago.
The bike started running ruff yesterday and I pulled the plug in the air box and oil came out.
Now I am concerned.

The site glass shows about 9/10ths full when hot on centre stand.

Should oil be in the air box?

Should I stop riding and drain some out.

When I changed the oil I did the usual (filter etc) and put in about 3 3/4 quarts, should not have over filled it.

 

[gsaddict]

Yes it is common. The crankcase breather vents into the air box. Drain out what is in there (should not be that much)
More builds up if you run the bike from the top of the sight glass to the middle or if you over fill the engine.
Try running it from the middle to the bottom as BMW recommends (now)

 

[jduke]

Route the crankcase ventilation out the back of the bike.

 

[flars]

Oil in airbox

Run the bike without the oil filler plug for about a half hour. That will adjust the amount in the bike. Wear old shoes and change your pants afterwards.
Now for the non-smartie-pants answer: I think 3.8 quarts is the proper amount, so if you filled the filter and added 3 3/4 quarts to the crankcase, you did overfill it. And maybe all the old oil didn't get out (my driveway slopes, so it can happen). You can get rid of any excess oil by pulling the oil filter off and dumping the oil. Clean up the mess and reinstall the filter.

 

[ANDYVH]

As long as the oil level is between the mid-point and the top of the sight glass there is littel reason to be concerned about the varying oil level in the window. If the oil level is above the top of the sight glass, then yes it is too high and it should be drained down to the acceptable range. A high oil level in the crankcase can cause excessive crankcase pressure which can force oil past the main seal and also up into the airbox.

Slight oil film in the airbox is normal.

 

[manybikes]

I think it is correct that I added too much after filling and installing the oil filter. I drained out enough last night to bring the level to the centre of the sight glass....really didn't take much.

The bike just suddenly started running rough, barely makes redline...not sure what the problem is.

Any suggestions

 

[FatChance]

The bike just suddenly started running rough, barely makes redline...not sure what the problem is.

Any suggestions

Verify that the ends of the throttle cables are properly seated at the throttle bodies.

 

[gsaddict]

Verify that the ends of the throttle cables are properly seated at the throttle bodies.

And that the pulleys are clear of debris (small stones have been know to lodge in them which knocks the balance way out of whack)

 

[breyfogle]

3 and 3/4 quarts (U.S. measure) is fine. A bit of oil in the airbox is OK also. Running rough has nothing at all to do with how much oil you added. Stop worrying and go for a ride !!