Tom is right. You want to isolate the problem though, so you have two choices really. Put the stock filter back in (I've never heard a good word said about the K&N filters) and see if you're good. Or, drain the gas, refill and see if it works, then you know your filter is OK. I would try swapping the filter first. Easy and fast. Point being, don't do both at once or you won't know what the issue was. Unless you do both, put the K&N back in and have the same problem, but then you'll have drained the tank for nothing.
Just a random thought, if I understand what you're experiencing correctly, it could be that the gas cap isn't venting right. Wouldn't make sense, but that is REAL easy to check. Try running with the gas cap open. I doubt that's it, but it's an easy first step.
"In a car you're always in a compartment, and because you're used to it you don't realize that through that car window everything you see is just more TV." R. Pirsig
Soon, we ride.
AKA JD Mader or you can call me "Dan" just not early for dinner.
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2008 KLR 650
RIP DM - Soon, we ride.
Last edited by Lockjaw; 10-22-2009 at 12:17 PM.