Im having issues getting my 2007 yfz450 to run properly, I was running a 165 jet with a xcelerator exhaust by DG performance with no lid on the air box with a k&n air filter and the quad ran good with the choke out but was struggling to idle with the choke in but ran strong in the low RPMs as long as the choke was out but in the high RPMs seemed as if it were running lean so I switched to a 168 jet and it now seems to run strong in the high rpms but dies out in the low RPMs and you cant goose neck the throttle because it seems as if it is too rich now. Also has a 45 pilot

Any help would be greatly appreciated.

Thanks,
Trevor

 

You need to go up on your pilot, that's where your engine runs from idle to 1/4 throttle.

 

Thanks any idea to what size?

 

I have no idea, I've never done a 450 but what most people do is either buy a jet kit or just buy a buch of jets ranging in size and keep changing them until you get it right. Maybe start with a 46 pilot and go up from there. Maybe someone else will chime in that's more helpful. All of my buddies that have 450's always had trouble getting them jetted perfectly. It seems they are sensitive or either my buddies didn't know what they were doing lol.

 

Alright thanks, I wasn't sure both kits I bought came with 2 pilots just a 40 and a 45 ill have to see if I can find a kit with over a 45

 

You should be able to buy just the jets. I used to just pick them up from my local dealer for like $2 apiece. Don't forget you can raise your needle (lower the clip) to richen up the mixture or lower the needle (raise the clip) to lean it out.

 

Thank you