Y09 CRF450R sputtering 1x/lap under hard acceleration

[Spokes574]

My bike started sputtering towards end of the day.
Under hard acceleration about one time per lap the engine seems to sputter as if it has low gas for about 1-2 seconds then comes back on strong again. Scary when it happens on the face of a jump. Bike turns on fine and runs fine after it sputters, but the sputtering comes back 1 lap later.

I thought it could be the spark plug, so I checked it was snugged and had propper gap and color was fine. The gas I use is high end Cheveron with 10% Torco Race fuel 110 octane, so its not the gas.

My thought was either a bad fuel pump or clogged fuel pump filter. Not sure how to tell the difference though. Any suggestions as to the cause of this problem.

Spokes574
California

 

[Ol'89r]

The first thing to do would be to check your valve clearance.

 

[Matt90GT]

buy a new fuel filter for the bike and make sure you filter you gas before pouring in the tank

You will want a new fuel filter for the pump:

honda fuel pump filter part#-

06160-MEN-A30

honda o-ring part#-

16711-MEN-A30
16712-MEN-A30

Then you want to filter the gas. CRFstuff.com has a great sock the fits in your gas tank fill to do that for you.

If you want more info, check to thumpertalk and search for this thread in the crf450 forums: EFI owners, bike bogging? "The fix" with pics