I think you said it was currently at second from top, which puts the needle down further into the Needle jet, making it slightly leaner from 1/4 to 3/4 throttle than the stock setting of 3rd slot down. If it were me i would go bsck to the 3rd slot, as AWK suggested.
Being lean can be dangerous and you especially dont want to be lean. If something doesnt seem to be running right,or while making other tuning changes.
Which way did the screw need turned , and how many turns out from sested did it end up.if adjusting the airscrew made the difference of coming on the oipe or not, you are definitely off somewhere else ( needle )
When i got my Blaster. It had the airbox lid removed, a dg pipe and oil oump unhooked.
The carb was super screwy.
The oil injection hole was left open, the airscrew was screwed all the way in rich, the carb cap gasket was chewed all to pieces and it was running the stock main jet. It was so sick i couldnt get it to come up in second with 13 tooth cog an 18" tires, and it topped out at a whopping 40 maybe 45 mph. Come a long way since then, and still got a ways to go,
Carbs arent complicated but can be finicky, start with the pilot jet and airscrew. Once you got it then you can do your needle and main. But put that needle back to stock, with the sirbox lid off, clean filter, and 220 main jet, you need that extra fuel throughout mod throttle.
And yes if your needle or needle and main jet is to lean it will keep it from making power.
Anyhow there are plenty of tuning guides out there.
Once you have checked float height, set the needle to stock, verified goo fuel flow, new plug etc.
Best thing to do is to get maybe one smaller and the next 5 or so bigger main jets. First find you a stretch long enough to hold WOT in 3rd or 4th from idle to redline. Before you make any changes, go out on the path get rolling just above idle in whstever gear your going to run and go WOT from that slow pace.not how it feels based on your current jetting and setup this should be lean, any popping weakness, etc.
Once you have done this and know where your starting, and how lean feels, sounds (make a second pass if you need to) then you are ready to start jetting. Put in the largest jet (around 270 or 280) and get rolling a good little bit above idle sameas before, then roll the throttle to WOT and hold it there, it should be noteably rich, and will probably cough and sputter, it will likely get to a point where it will clear out and go. Try to notice how it feels, sounds, acts, this is a super rich engine. Work your down the jet sizes doing the same run each time (same gear, same speed,same path) noting how it acts each time. As you go down the jet sizes, it will eventually clear up an start running better. The biggest jet that runs clean and smolth from low rpm to redline is likely on size bigger than you will end up with, note this size, then drop one size smaller and do a plug chop run. You might need abigger area to do plug chops.
Anyhow the idea is to teach yourself how to hear or feel a rich or lean motor, with enough practice you can start to hear rich or lean from the parking lot as your buddy rides across the hillside. Being able to tell rich from lean is as important as knowing how to leak test or knowing how to mix your gas.
If you have any trouble reading your plug chops post a picture up here, some of the guys here have handled more chopped plugs, than autozone has stocked in the back.
