KZ400 single carb conversion

Hi!
I'm badly looking for advice on jetting my single carb conversion.

I've got a KZ400 twin with the 11th hour 2-1 intake and a Mikuni VM34. It starts, idles and rolls of ok but not much above that. I can take it to maybe 50mph/80kmh. I would say it runs as it should up to about 1/4 of the throttle range. (I've made a tape measure and marking on the throttle grip)

Everybody talks about the pilot and main jet but there are a couple of other parts to tune on the VM carbs. Throttle slide, needle jet and needle type. Aren't those important enough?

My setup right now is
Throttle slide 3.0
Needle 6DH7 2nd position from highest
Needle jet O-4
Main 170
Pilot 17,5

Any suggestions and guidance would be greatly appreciated!

Did you sync the carb?..... Lol. I havnt done conversion 1 into two. Doesnt seem logically like a great idea tho because cylinder vacuum will differ therefore so will the fuel. Def need the correct jets and needles and heights tho and yea itll cost a lot of your time, just like this post im writing, time youll never get back unless you get lucky and find the right info.

Did the people who sold you your manifold give you any guidance?


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