Quick Q on main jet and needle?

Ok there is one thing that i have been wondering about..

I did some basic jetting on my DRZ 250 was backfiring through carb anyways...

Now when you change the main jet obviously your effecting the WOT mixture but When you change the main jet and leave the needle the same do you effect the 1/2 to 3/4 throttle range where the needle is still down the jet tube?

on my drz i changed the pilot from a 37.5 to a 40 and the main from a 127.5 to a 130. and i think 2.25 on the fuel screw.

i have been playing with the main jet had it to 135 then down to 132.5 then tried a 130 and the 130 feels the best...

even though there is some over lap you should treat them as individual circuits.

In simple terms, the main affects WOT, but the effect of the main begins at about 7/8 thottle. The pilot and fuel screw are for idle, but the effect dimishes as you get closer to 1/8 throttle

well i think i understand, i already know the pilot jet effects the idle, but logically i thought increasing the main jet would both richen the midrange and WOT operation seeing as for midrange the main jet is partially obstructed with the needle jet then at WOT the main jet becomes wide open as the needle jet comes completely out of it????

so in midrange you have the same dia of needle jet down a slightly larger main jet hole hence more fuel = richer mixture??

Im just not familiar with the way the needle jet actually interacts with the main jet / jet tube

I want to richen the midrange and im not sure that i have or not by increasing the main.

From what i have learnt the mid range is really only affected by the needle -to- needle jet relationship.

so even though the main jet is bigger the fuel has to get past the gap between the needle and needle jet. That is why you adjust the clip position or change to different tapered needles if youwant to change midrange characteristics.

as long as you dont change the end demension of the needle the main jet and clip position have very little effect on each other.

you want to richen partial throttle or wot?

jetting is relative to throttle position not rpm.

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