ID this jet (help a noob)

So I'm trying to do a little experimentation with my main jet size. After describing the jets to someone over the phone they thought I had "small round" Mikuni jets. So I bought some in the appropriate sizes but they're all wrong.



So what's this tiny main jet called and how do I make sure I order the right part next time?

Z1enterprises lists a carb rebuild kit (out of stock) for my bike but IDs the carbs as N100.606 series (not sure what that means)

I see Mikuni "pilot" jets or "low speed" jets that have this number and look right but I don't see any identified as mains.

Are you sure that is a main? That looks more like the N100.606 pilot jet.

The BS 38s used on the kz750 twins are different in that both the pilot and main jets are screwed into the bowl and not the carb body like the the other BS type carbs are.

Yeah, this came out of my float bowl just above the drain screw. It's the main jet. The pilot jet is also in the bowl, but you get to it from the top of the bowl.

If you look at the carb rebuild kit from Z1 you'll see both jets pictured. The long one is the pilot and the little stubby one is the main.

www.z1enterprises.com/ItemDetails.aspx?i...-1979&item=KL18-2464

I'm looking to swap my 125 main with a 120.

So all the N100.606 Mikuni "pilot" or "slow" jets are actually what I want after all?

So to help any other's with these carbs, the main jet is actually a pilot or "slow speed" jet. Picked up a couple and they fit perfectly.