i'm running 120 DJ's with no probs.

 

The Jet and the Needle work in conjunction with each other, but the proper Jet size is the MOST important thing. It controls the OVERALL amount of gas that's going to get into your engine under high-throttle conditions. at wide-open, high RPM, the needle doesn't really matter at all.

The Needle just controls where in the curve how much gas comes in, basically. If you think of the needle as "plugging" the jet, as the slides come up under vacuum, the needle slowly moves out of the way of the jet, allowing more gas in.

The different tapers of certain manufacturers' needles determines if MORE gas comes in SOONER in the RPM curve. And if you set the 'clip' on the needle further down the needle, for example, that means the needle gets out of the way SOONER in the RPM curve, for (hopefully) more power in the midrange, if you get it just right.

But Yes, stock needles with the PROPER jet size would be WAAAAAY better than what you have right now. Then, when you get the jet size right, if you're feeling frisky, you can mess with different kinds of needles and clip heights.

(The reason I have STOCK needles is: when I got my bike the carbs were absolute trash; and the DJ needles in there were so corroded they were worthless. BUT, the previous owner had all his original stock carb parts he removed when he installed the DJ kit. So, I just put the brand new stock needles back in there and it's working fine for me. So, basically, I have a Stage 2 Dynojet kit (but with stock needles.))

Most "Jet Kits" like the Dynojet include new needles with a clip system, stronger slide springs (so the slides will come down faster when you're off throttle), and an assortment of main jets. That's about it. So if you have aftermarket needles in your carbs, you can probably bet you have the stiff springs too; so save $100 bucks and just buy a few jet sizes from DJ and you'll probably nail it.

 

alright man. thank you. i appreciate it! lots of good info