yes, another jetting question

[Doc Brown]

My friends GP 300 is on stock carb setting, except that the main jet is a 170 instead of the standard 175. I checked the float height and reduced it a bit as it was set too high and the carb spilled gas as soon as you leaned it over 20? degrees.

So the current set up is:

N1EF needle in the third groove, main jet 170, pilot jet 42, AS 2 turns out.
Altitude: 660 to 1200 feet
Temperature: 88 F
Premix: 60:1 Silkolene Fuchs Titanium Oil

Surprisingly the bike runs very well with the N1EF only burbles a bit down low. Its mostly ridden on the pilot jet, normally does not get high revs. Its overly rich and always has much spooge on the exhaust.

I have a NECW needle on the shelf and would like to try it. I do believe it would work very well with the current jets but I don't want to ruin his bike. If it was mine I would not hesitate a second and try it.

Can anyone tell me the differences between the two needles. I know the NECW is leaner than the N1EF but I don't know much about the N1EF. I expect the bike to run leaner everywhere without the danger of seizing.

I can't ride behind my buddy because his GG smells like its spraying pure gas out of the exhaust. I had a headache last time I followed him...