We need to know what # slide you have....
I think the n1ef is horrible - but note that to get a leaner needle to work well, and it does work much better in my opinion, you need to go up one or two sizes on your pilot jet (e.g. 45 pilot) and reset your air screw and idle screws.
Based on what I know from talking to Les - I would start with something in the range of a keihin ddk needle on #3 or #4 clip position and a 45 pilot/178 main. Assuming you have a #7 or #8 slide. Gofasters stocks these needles or something close to it. You can also order from sudco (u.s. importer for keihin) - but they usually have a required minimum order (this may have changed with the bad economy).
Other options for carb tuning are to send your carb to RB-Designs for his mods - he makes internal modifications to increase the sensitivity of the idle/pilot circuit and dials in the jetting.
Frankly, if it were my bike, the first thing I would do is to measure the squish and have Ron at RB-Designs machine the head to dial in squish and compression for your altitude range and fuel - this is the biggest bang for the buck - better efficiency and bottom end power.
For jetting, I have ridden two 300s back to back - one with Ron's carb mods and my own with an LTR jetting kit - The RB bike pulled more cleanly and reved higher - carb bored to 39mm with divider plate installed on the RB carb.
jeff
p.s. I am a fool to reply to jetting threads - it sometimes turns into a conversation similar to "which chain lube is best" or "which 2 stroke oil is best". Someone can have a jetting combination that works well for them on a given day - but the key is to have a setup that is set up right so that it responds easily and correctly to user adjustments and isn't "finicky". e.g. if you go up in altitude can you adjust via the correction charts in the user manual and be pretty damn close to "spot on" after having a good baseline at close to sea level and 50 degrees, etc. And for minor changes, you can just tweak the air screw a tad and be on your way...
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