Sigma 6 jetting kit now installed on bike

[Jaede]

I noticed a lot of you checked out my post when I asked if anyone had used the sigma 6 jetting kits on their KDX'S so I thought I should repost to let you know the results. The kit consists of three main jets a #150, #155 and a #160, one pilot jet #48, a drill bit and screw for removing air screw cap which was useless as the air screw dosnt have a cap, it also has various metal washers and plastic spacers to change needle position also useless as the needle on these carbs is adjustable, there was a lot of paperwork too, mostly generic jetting info and some misguided info about needle position for KDX. I'm running a fresh motor, boyesen rad valve, fatty pipe, I cleaned up the ports when I rebuilt it, put in bdk KIPS valves, After playing around with the jetting, needle position and air screw I am very happy with the way that my bike is running using the #155/#48 needle in middle position and air screw 1.25 turns out, I could have done it alot cheaper though by just buying the jets without the kit as at $55 US I think it was a bit expensive but Sigma 6 were polite to deal with and sent me a second kit after I complained about the kit taking too long to arrive (1st kit arrived day after I complained lol) so if anyone wants a cheap kit to try $20 and its yours plus $5 for postage

[Timtee]

Maybe I missed it, but there was no needle in the kit for that price?

[Jaede]

Nah you didn't miss a thing, there was no needle in it

[Timtee]

Wow. And I guess I shouldnt even ask if the jets were genuine Keihin instead of some chinese jets.

If you really want to be happy with the jetting, try a DEL and CEL needle.

[Julien D]

Those jets sound awfully fat to me.

[Jaede]

Wow. And I guess I shouldnt even ask if the jets were genuine Keihin instead of some chinese jets.

If you really want to be happy with the jetting, try a DEL and CEL needle.

Yeah don't ask lol, I wouldn't recommend anyone buy these kits, they work fine but way over priced, I swapped the jets back to Keihin jets of the same size and there was no difference at all so I think they work just as well, ended up chucking in a #150 main this morning and now I am happy with how it goes even with my 265lbs on it, it still wants to get up on the back wheel for the first 3 gears, got bike running well but cost more than it should have... Lesson learned

[Jaede]

Those jets sound awfully fat to me.

What do you mean fat? I swapped out the main to a #150 today and it goes a lot better

[Julien D]

Can't imagine running a 160 is all, so I think it's curious that it's even in the kit. 155 ends up being too big for most setups as well. I'm sure it does do better with the 150.

[Jaede]

I think the kit is just a rough guess, It works but wouldn't recommend paying full price for it, I am happy with how my bike goes, was quite surprised at how quick the kdx goes for such a little bike, Haven't really owned a bike that small since my very early teens, although it looks a bit funny when I ride it due to my size, but I think I understand why they have such a strong following, they're a very capable versatile bike