I think my jetting is off?

[Honda0001]

I have a brand new 2006 KTM 250SXF. I find when I rode it up the street to test it backfired like crazy on decel and was cutting out at times. What needs to be increased/decreased to change the mixture, sorry again i still haven't got my manual. I'd imagine everything is stock settings at the moment.

Many thanks

Regards

Marc ?

[monkeymotocross]

how did u find a new 06?

here they were sold out right away!

just adjust the air fuel mixture screw

[MikeSD]

it may need more than just a turn of the fuel screw.

JD jet kit is pretty much a standard "mod" for all KTM owners.

[Honda0001]

how did u find a new 06?

here they were sold out right away!

just adjust the air fuel mixture screw

I live in Europe (England)...

KTM are great here, My friend has his 2007 already ?

[Honda0001]

it may need more than just a turn of the fuel screw.

JD jet kit is pretty much a standard "mod" for all KTM owners.

Ok thanks, I remember seeing a guy at the track and him saying he had to have his carburettor set up professionally because they come like bad or restrictive or something, ID remember exactly. But he was also talking about how the expert racers have them sent off to dyno/rolling roads to have them set up proffessionally to get the maximum potental from the bike/jetting.

[JohnnyMac]

I'd look at adjusting the fuel screw first (richen), then maybe going up one size on the pilot. Mine was doing the same then after going out almost 3 full turns on the fuel screw I went one size larger on the pilot and the bike runs great.

I have the JD kit on my 453 and also put one on my SXF. I took it off the SXF after playing with it way too often. I put it back to stock and the bike runs great. I wasn't too impressed with his kit on the SXF before and after I had the 305 kit put in.

[Dave Hopkins]

Decel poping is not a jetting issue, it is an air leak at the head pipe/cylinder head jucktion. It must be sealed with hi temp silicone sealer which must dry for no less than a couple days before you start the engine.

Jetting on the SXF is certainly in the ball park from the factory (unlike the big bikes), the accelerator pump is another issue.

[Peerless]

Ain't it great!!!! I remember my first ride up and down the street with my shiny new 450. Poppin and fartin all the way!!!! KTM should be ashamed of themselves. Remember, the JD kit will only get you close, don't be afraid to change something, James will give you advice.

[exctrailrider]

(Sorry for the newbie question) Is the poping hard on the bike? I got to test ride a slightly used 450mxc and i noticed that if i let off the gas fast it popped quite a bit but besides that it ran really strong and started extremely well.. should i be concerned about the popping or is it just annoying? Thanks

[ACS]

Often on the 250SXF the popping is because the hot start is not returning to its seated position. I'm not sure why it happens on the SXF but it does. Check that you can hear a little thumk noise down on the carb when you release the hotstart. Its not a cable issue, its the carb plunger / piston.