need help tuning nibbi n26

[jeyx2x2]

=Idle is dialed.
=Air/fuel mixture is good indicating pilot jet is okay.
=Blipped the throttle and i believe it returns to idle rpm immediately.
=Ride test:
+Closed to 1/4 throttle - runs perfect.
+1/4 to 3/4 throttle - sputter
+Full throttle in 4th gear sounded crisp.
=Moved needle clip up one to position 2.
=Blipped the throttle and hear loud vacuum (guessing its lean)

main jet #110
pilot jet #40

Im not sure what to do, with current needle position its lean, put if i lower the clip, it will be rich. And from my understanding pilot and main jet dont need to be touch nor the air/fuel mixture screw since closed to 1/4 throttle and full throttle is good.

I know theres overlaps of these circuits but not sure where and how so i am not able to continue with the tuning.

Im Stomped. Whats the next step i should take?

[jeyx2x2]

im gonna try different needle. just bought a kit. hopefully a bigger needle will do the trick.

[krat]

Everyone explains and describes carb adjustment as if there were a third place where the carb pulls gas from during that 1/4-3/4 throttle range before the carb goes into wide open mode.

There isn't. The mid-throttle range slide/needle mechanism is a limiter of what is coming out of the main jet.

Go to a 115 main jet and reset the air/fuel ratio. I have been running a 115 for 6 years and it works fine. Some here are running larger mains than 115.

And check your valve settings. Badly set valves are like water hitting a dam.

[jeyx2x2]

someone in another forum told me to revert thr needle position to what i previously had it at and to make sure float height is up to spec. Afterward everything seemed better but still a tad bit rich. This is wierd because in a small section a little pass 1/4 open the mixture is lean.

With these issues i get what you are saying about going with a bigger jet. Im thinking bigger jet and a lower needle.

Im not gonna try this yet. I was suggested to try a new spark plug and leaning the mixture after mentioning that i couldnt start that bike after riding around in low rpm for too long and finding a black and wet spark plug. But I forget to mention that bit of leaness passing quarter throttle.

Thank you krat for the advise

[jeyx2x2]

i was thinking about this, with it being rish and without the pcv in yet, i think i should down jet and use a different needle. im gonna have to experiment.