[loops450r]

Need a little direction in jetting.My 03 450r is all stock and has a little off idle bog and a backfire on high speed decleration, starts good idles smooth and runs well other than that.I just wanted to get some expert advise from you guys.I live in shelby nc elevation 853 and ride mostly in lenoir nc elevation 1182 any help would be appreciated thanks.

[Asmith]

Open up your fuel screw 1/8th of a turn at a time. Should be able to adjust the bog and decel pop out. The R's don't come choked up so they don't need the jetting help that the X's do.

[loops450r]

Thanks agent I appreciate the help alot.Do you think I need to leave the jetting alone other than the fuel screw or do you think I would benefit from a jd kit with oring mod.I came off a quad so the fcr is new to me.Traded the ltz400 for the R and I love the R I didnt Realize how slow my heavily moddified Z was the R rocks just like this web site thanks again.

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You can'r go wrong with a JD kit, the guy thoroughly tests everything he sells.
Your problem can likely be fixed with a fuel screw adjustment done as AS suggested, but that doesn't mean it can't be made to run even better. Doug

[Darkoverlord]

I highly recommend the Boyeson accelerator pump cover. It will take away any low end bog you have. EVERYBODY that I know with a CRF (Except the rich guys with the '07s) has one. The very first mod that should be done on any older CRF. IMO

[JAWS]

On the less expensive side you should do the o-ring mod to the accelerator pump arms. Has proven to be a cure for the bog.
Joe

[SoCal450R]

I put the jd kit on my 06 450r, can't tell you the difference as to I did it before i rode it. but was having decel popping with a 172 main and the 42 pilot, so I put a 45 pilot in and messed with the fuel screw and that helped. I did e-mail James Dean(jdkit) he recommended running a 180 main with a 45 pilot at 1 1/4 out on the fuel screw. Seeing as my kit didn't come with a 180 main....I haven't done that yet.