Check Your Air Filter!

mcnut

mcnut

New member
While cleaning the air filter on my son's 2011 250, I found a tiny hole caused by a raised rib on the seat pan (at center of photo). To save future air filters I removed the rib with a grinder.

Better check your filters closely and modify your seat pan or you could suffer premature engine wear.

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Part of the problem is the rear of the fuel tank does not have any type of retainer. So the tank is bouncing around and the seat moves with it.
This chafes the air filter.
 
I suggest putting a thick piece of foam weatherstripping across the frame behind the tank. With enough compression of the foam, the tank will stay in place.

In the photo above you can see where the factory grinds the ribs off; some seats may not be as well ground as others. Also the filter support frame can be trimmed at the top by a millimeter or two to reduce the height of the filter when installed.
 
Anyone want to post up some pictures of how they've modified the seat and how much material they have removed? Has it solved the problem entirely??
 
I think most of this has to do with rider weight and where they sit on the bike.

Heavy foam under the tank and maybe even a bit over the tank where the seat touches should help a lot. Aggressive riding probably puts more force on the seat pushing the hook down into the filter. Maybe a couple of pieces of hard rubber should be taped to the frame to support the seat better.

My seat hook just clears the filter. I trimmed the top of the filter support and did some slight cleanup on the ribs. I also tend to hold the filter a bit lower when I install the spring anchor. I sit farther back than most guys and don't "get up on the tank". No problems with the air filter.
 
I'm by no means a big guy 75kg 175cm. Nor am I as aggressive as I'd like to say I am, though I do spend alot of time moving around the bike. Typically stand up most the ride and only really plant in for the tighter bermed up bends.. I also experienced tearing along one side of my seat from gripping with my knees.. Just little qwerky things..

I have been slowly shaving my seat plastic down to try and stop it rubbing.
 
I disagree the problem has anything to do with a floppy tank or rider weight. It's a problem with the seat pan. The little rib just needs to be ground away.
 
I think the movement of the seat is definately what causes the wear.. In saying that its some part of the underside of the seat that is making contact. You call it the rib. I'm unsure if it is, or if its a front corner. Thus what I have asked for pics of what people have changed.

Heres some damage that occurred to my first filter.
Rapedfilter.jpg
 
I wouldn't necessarily suggest doing this inside, or with a filter soaked in mineral spirits, but since filter seams are flame-joined, you might try passing a torch lightly over the ripped area and see if you can re-seal it.

Just threw out a fairly new Twin Air for the same reason, and that led me to trim the top of the filter cage and try to force the filter lower when mounted. I'll have to have another look at the rib Jan said was offensive.
 
mcnut said:
I disagree the problem has anything to do with a floppy tank or rider weight. It's a problem with the seat pan. The little rib just needs to be ground away.
Click to expand...

You are correct. My 2008 had the same issue, ground it away and no problems after.
My 2011 does not have the issue as the 2008 did but the molded rib appears far smaller and less abrasive. I wonder if the molding process allows some extra material to stay attached on some seat pans during manufacture.

On a side note my 06 and back never had this issue, old style seat base sub frame assembly.

Roscoe
 
Are you saying to grind down the orange part?? The pink?? Or both??

Good idea about trying to heat seal it.. I can imagine the outcome already.. haha! I don't trust my ability to clean it well enough to get the oil and the turps entirely out of it. All have my filters have been pretty well damaged all over by the time it wears through. I was using a big dollop of grease on the top that also acted as a lubricant/buffer.
 

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Jakobi said:
Are you saying to grind down the orange part?? The pink?? Or both??

Good idea about trying to heat seal it.. I can imagine the outcome already.. haha! I don't trust my ability to clean it well enough to get the oil and the turps entirely out of it. All have my filters have been pretty well damaged all over by the time it wears through. I was using a big dollop of grease on the top that also acted as a lubricant/buffer.
Click to expand...

The orange part you have highlighted.
 
Clean the damaged filter real well ending with laundry detergent or dish soap, rinse, let dry, and fix the hole with hot melt glue. Has worked great and held up well on the custom foam pre-filters I made for my Ducati. Holds up to No-Toil, not sure about petroleum base filter oils/solvents.
 
The more I look at the air filter pictures, it does not look like a chafing issue.
Looks like the filter is pinched by the seat tray. A chafe would be more of an oval shape indentation in the foam.
 
Pinch of chafe.. same thing different slightly..

Its the cause of the rib on the underside contacting the top edge of the filter cage.. I believe this happens during impact downward on the seat.. I don't think it occurs during fitment of the seat, but it very well could be..
 
If you can relocate the bottom pin on the air filter cage, the whole air filter may drop down just enough to clear the seat pan.

I'll try my Twin Air billet filter cage and see how it fits.
 
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