Pocketbike jetting.

[{.bLanK}G_o_D]

I was thinking more like a 2mm.

[Nutter34]

How do you plan on getting it centre? Or don't you think it's THAT crucial?

Maybe a very small hobbie lathe. Put the jet in the chuck and that way it should be more centre? It should at least be more consistent.

[{.bLanK}G_o_D]

Yip a wee lath would do it. We'll probably try the wee drill press first, as long as it is pretty close to center by eye, I don't think it'd be a huge problem. We'll find out soon enough

[Spearfish]

I was drilling jets out to find the one I needed, but only because I didn't have the ones I wanted.
One problem is you tune with rich jets and work down until WoT pulls the best 1/3- is needle height, 1/4- pilot jet, idle- up air screw.
You run a huge risk of seizing going the other way, considering your pinning it doing plug chops, unless you have two?
But then I was tuning a big-bore cylinder from std, maybe its not so many steps just tweaking.