rich jetting?

[TRX400EX02]

For the first 15 mins of riding my 400ex the jetting seems perfect. But after 15 mins it seems as though the jetting richens up. It will occasinally bog and stutter, and in neutral it will stutter and cut out for a second if you rev it real quick. Im not sure what the problem is. Do I need to rejet? Or is a air/fuel mixture screw adjustment? Or is it something else.
P.S. Those 15 mins are with the engine warmed up.

[IanCFitz]

Might want to let us know what jets you are running...

you have jetted it right?

[TRX400EX02]

148(stock i believe) currently. I started with a 146 like the FMF jet kit recamended but it wouldnt make it past half throttle without cutting out and it was backfiring like crazy. So i went up to a 150 and it ran good for a couple of months but then it start bog and eventually fouled a plug so now Im back down to the 148.

[IanCFitz]

Sounds like your float may be sticking.

If you have a slip-on and a K&N you would definitely need to get larger than stock jets.

There's definitely something else wrong.