[1BigRedThumper]

I have a 2006 CRF450X, Ever since I bought this bike (new), I have noticed one particular problem. When I goose the throttle real quick, the engine sputters and bogs for a moment before the gas kicks in and the engine revs up. From what I've heard, this is a pretty common problem with the CRF450X. Does anyone know how to solve this problem? I'd like to have a more snappy throttle response without the hesitation. I would appreciate any feed back I could get on this matter.

[JimDirt]

Welcome to the site !!



Questions first

please give the details about what is done to the bike

Jetting

Airbox (mods/no mods)

Pipe(stock/aftermarket)

Elevation (i am assuming Sea Level which would necessitate a #45 Pilot and #165 Main as opposed to the stock #42/#142)

Also , is this while riding or sitting on the stand ??

What i found to be the "cure" for my 06 was jetting , opening up the airbox and the Quickshot 1 , most importantly , the jetting and Quickshot

[mossman77]

I have a 2006 CRF450X, Ever since I bought this bike (new), I have noticed one particular problem. When I goose the throttle real quick, the engine sputters and bogs for a moment before the gas kicks in and the engine revs up. From what I've heard, this is a pretty common problem with the CRF450X. Does anyone know how to solve this problem? I'd like to have a more snappy throttle response without the hesitation. I would appreciate any feed back I could get on this matter.

You need to do the accelerator pump (AP)/o-ring mod to get rid of the slop in your AP linkage. Common issue on a bunch of '06 and prior CRF models (150R, 250R, 250X...). Here is the link: http://crfsonly.com/howto/ap-mod/profes ... -guide.php

[JimDirt]

Just as a FYI and to add to what mossman77 said , i did not do the AP O-Ring mod , and do not have the bog anymore after doing mentioned mods (along with a #65 Leak Jet and cutting out the top only of the airbox) , you can physically adjust most of the bog out with the screw , but the larger AP Pump Cover and the leak jet and jetting "should" do the trick , i personally do not like the QS 3 with the adjustable leak jet , its too much tuning for so little gain and its not as accurate as they claim , its much easier and accurate to just replace the leak jet with 1 size smaller (larger jet number) and find a QS1 or QS2 and be done with it (and they are both much cheaper than the QS3)

But you can do the O-Ring mod without any downsides , but its not the only solution to the bog fix and may not completely rid the issue without proper jetting , etc

[1BigRedThumper]

Right on, thanks for the information guys. I'll try the O-ring and air box mods to see if that helps. I'm going to be installing an FMF (Mega-Bomb) pipe with a Big Gun (Evo-R) slip-on as well. So I just need to make sure I get the proper jetting, then I should be good. Thanks again for the tips.