2009 EFI, oil in airbox

Rubicon

Rubicon

Scooter
I was out cleaning the bike and decided to open up the airbox for the first time. The whole lower section of the box is filled with oil. The oil looks super clean so im thinking someone overfilled it at the 500 mile service. Bike just broke 2000 miles, I bought it with 1400. I cleaned all the oil out to see if it fills up again. I did some research and they said the early Bonnies had some issues with oil in the airbox but i could find nothing on the later EFI bikes.
 
RyanRobot99

RyanRobot99

Street Tracker
The crank case breather hose is connected to the airbox for ventilation. If you have a little oil, it's perfectly ok.

There shouldn't be more than you can wipe off with a rag. If you have a puddle there might be a problem. Overfill?

If it really bothers you, pull the hose, cut it short and put a little breather filter on it. You can rest the filter on the crank case. But then you'll have to wipe the top of the case. That what you have to do when you get an air box eliminator kit. If you do that, dont forget to plug the airbox where the hose was.

Side note:

I recommend you get the BC or NewBonneville airbox removal kit and remap with arrow 2into2 map. I'm not a fan of the airbox.
 
Rubicon

Rubicon

Scooter
Yeah i think i still have a year of warranty on it. Im going for a ride right now, its 77F here so ill see if it fills with oil again and then go from there. It was a puddle of oil, i had to use a bunch of paper towel to soak it up then i wiped out everything. Ill let you guys know if it fills up again.
 
dschief

dschief

750cc
You will get more oil in the airbox with a new engine, as it breaks in, than you get with an older broken-in engine. The crank case vent carries all the blowby to the airbox, which will carry some oil with it. It depends on your maileage, how the engine was/is broke-in. I wouldn't too much unless it continues, and you start noticing you are having to add oil. How many miles do you have on the bike?
 
Rubicon

Rubicon

Scooter
2134 as of tonight, like I said earlier I bought it used with 1400 miles, it was right at 2k miles when i noticed the oil.
 
dschief

dschief

750cc
Yep, I would say it was still breaking in at that mileage. The previous owner may have never checked the airbox, and what you have is the culmination of 2134 miles of vapors from the crankcase. Check it again in a few weeks and you may have very little to none. If you have a pool again, you may have a problem (ie.rings didn't seat properly). Then you should worry.
 
Kappy

Kappy

Two Stroke
Check your oil level as well. Because the oil in the airbox has to come from somewhere if it is not caused by overfill.
As you have cleaned it out I suggest just observe it and in case it has filled up with the same amount again after sometime you may have a problem with the breathing / internal pressure of your engine.
 
six by six

six by six

Two Stroke
Yeah the crankcase breather goes straight to the airbox. It's what it is supposed to do. I don't know the logic behind it. When I removed my airbox I ran a longer tube down the bottom in front of the swingarm. It drips a little oil now in front of the rear tire but only a drop at a time so no big deal.
 
You must log in or register to reply here.
Top