Air filter issues

[briang123]

I have an issue here you guys may be able to help with. 2012 with 13000 miles on, daily rider/commuter. Garaged at night, parking lot in the day. Anyway a couple weeks ago I opened the air box for the first time to check the filter. The air box was nice and clean, and figured Id change the filter over the holidays. Put it all back together, and back to routine riding. My next two gas ups my fuel milage had dropped from 40 mpg to 30 mpg. Well yesterday I opened the air box back up and found fuel and water contamination inside the air box. The seal around the filter looked OK, and the box cover looked tight. It does look like fuel was all around the center screw stud and maybe seeped through the filter gasket at that point. I don't know....I know whatever I did was self inflicted, just don't quite know what it was.
Any thoughts? I put a new filter in yesterday, cleaned all the seals real good, double checked everything seated good and tight. I'll check it again next weekend.
Thanks for any help

 

[Yamaguy55]

Are you sure it isn't condensate from day/night temp changes? (Sweating like drink glasses in the summer) If slight moisture, you can prove that by pulling the little clear plastic/rubber bulb like drain cover at the oft rear. It often has a bit of oil in it from blow by, if suddenly full of water, how did it get in? The airbox lid, if properly screwed on, shouldn't leak unless submerged, and if it is, you have other problems to deal with. 8)

Fuel mileage can suddenly drop for any of a number of reasons. Different rule delivered to gas station, different formula due to different refinery, different annual requirement s (winter vs summer blends) and any of a number of other things. Fuel consumption always increases when outside temps drop. Cooler air=denser air which contains more O2, which needs more fuel for correct A/F ratio.

Last-if the temp sensor in the air box is not making good connections, it can make the ECU think the engine is receiving inlet air at some other temp and adjust fuel accordingly. The dash temp for the ambient air we have is driven my that sensor. It r=tends to read anywhere form 5 to 10 degrees higher than ambient due to where the airbox gets its air behind the engine. So if you ride with that displayed, and pass an bank sign with a temp display, your bike should show somewhat warmer. If wayyyy off, look at the sensor and or wiring. It is that little thing at the back of the airbox with the wire going to it.

 

[BUGKILLER]

Check to see if your breather lines pulled off your gas tank.

 

[briang123]

Thanks for the replies. I did have a oil/water sludge in the little nipple, and in the photo you can see it looks like rust. There was a little pool of water laying there. Condensation is one of my first thoughts, especially as my commute isn't very long so I doubt everything gets warmed up thoroughly in the winter mornings. As to the gas milage, I know my fuel usage real well on this bike, always reset my odometer at every fill up. Never ever seen an immediate 25% drop in milage. Thats the thing that raised the red flags. And going from a clean dry air box to this mess in 2 weeks has to be related to my issue. Im going to double check the breather tubes (may have pinched them) and the temp sensor.
Thanks

 

[racer1735]

Recently, I opened my airbox for the first time during my ownership, and when I raised the tank, one of the fuel lines (either breather or overflow, not sure which?) pulled off. I reattached it, but the other line was so tight in its routing that I had to pull it up manually to get enough slack that the tank would rotate back on its pivot. When I lowered the tank to button everything back, those same fuel lines needed pulled back down to go thru the clamp on the front of the engine block. One of them did with about the same amount of line to extend out the bottom of the bike (as original). The second line only had about an inch of line present past that clamp. I pulled the tank again and noticed that the fuel line had gotten jumbled up when the tank was put back down....maybe would have caused issues, I'm not sure. But I straightened the line out and routed it properly.

However, it is still MUCH shorter than the other line and doesn't extend out the bottom of my crash plate as it originially did. Not sure what's wrong, but the bike runs fine and I"ve noticed other photos where the lines aren't apparent in hanging out of their crash plates.

 

[Nimbus]

As long as we're talking about air filter issues how did you guys get the stupid rubber plug out that hides the center screw? I tried to check my filter and couldn't get to it?

As for the mileage drop, I'm convinced the S10 hates the cold. My avg mileage has been crushed by the cold. I've taken to stuffing a rag into the intake in the fairing to let the engine warm up/keep warm when it is in the 20's.

 

[briang123]

I just grabbed the plug with a pair of pliers. The first time it was pretty stiff, but it popped right out the second time. I saw a drop in milage last winter, wether from temp or winter blend I don't know, but never anything like what I saw this past 2 weeks.