[SEBZX79]

Hey Guys,

I bought a 08 450xc last week and the dealer gave me a 175 main jet to put in. I put the jet in but from the begining has issues with the bike idling. When cold it will not stay running at all until I put the choke on or keep the rpms up. I am in NJ at almost sea level what would you guys recommend as be best setup.

Thanks.

 

[trailrunner]

Hey Guys,

I bought a 08 450xc last week and the dealer gave me a 175 main jet to put in. I put the jet in but from the begining has issues with the bike idling. When cold it will not stay running at all until I put the choke on or keep the rpms up. I am in NJ at almost sea level what would you guys recommend as be best setup.

Thanks.

Is the bike stock? We are running a JD jetting kit and using the 170 jet with the JD needle on clip 1 or 2 (cant remember). What you are discribing is normal when the bike is cold, that is why it has a choke button you pull out while it is cold.

 

[SEBZX79]

Is the bike stock? We are running a JD jetting kit and using the 170 jet with the JD needle on clip 1 or 2 (cant remember). What you are discribing is normal when the bike is cold, that is why it has a choke button you pull out while it is cold.

The bike is stock, I am running 175 currently with everything else being stock. The bike will not idle unless it is FULLY warmed up and them dies out half the time as well.

 

[Lost Down Under]

Sounds as though your mixture may be a little too rich.
Have you adjusted the mixture screw?
When you do adjust it, only turn it about 1/8 at a time.
A good investment if you haven't already done it is to put in a thumb screw - https://www.ktm-parts.com/mm5/merchant.mvc?...y_Code=KTMHEATV

 

[trailrunner]

Sounds as though your mixture may be a little too rich.
Have you adjusted the mixture screw?
When you do adjust it, only turn it about 1/8 at a time.
A good investment if you haven't already done it is to put in a thumb screw - https://www.ktm-parts.com/mm5/merchant.mvc?...y_Code=KTMHEATV

Put the 165 back in and see how it runs

 

[SEBZX79]

Put the 165 back in and see how it runs

The stock one was a 170 in my bike, I thought that these things came very lean from the factory. THis is why I changed the jet.

 

[trailrunner]

The stock one was a 170 in my bike, I thought that these things came very lean from the factory. THis is why I changed the jet.

I had a brain fart and ment 170. If you leave everything stock they run very well, but if you go and remove the snorkel, remove the baffel in the exhaust and open up your air box ya it will lean the bike out.

 

[kiwi-craig]

the ktm main jet size is bang one with the stock needle, on our stock 450 anyways it would not take more main at all, instant break up at high rev - rich....... we went 45 / one clip richer on the stk needle / 165 main

from the factory they have the idle circuit lean - needle lean for emissions to get the green sticker

JD needle put more fuel in down low, but are leaner on top (hence bigger main)