clarification on changing main jet sizes (yet again, sorry)

[headshrink]

I find the differences between the original and new engines aren't dramatic, with the same carb settings, but there are some differences, hence the desire to work that out. Prior to replacing the 1st engine, I was on the verge of fixing the long standing "phantom surging" at cruise. While I had spent most my time working it out in the idle screws, but frustrated when it would still give me a little lean surging, when obviously lethargic from a stop, I realized the point I was needing the adjustment was really more the needle height then mixture screws. Raising it one washer seemed to really help both the surge, and improve mid-range, which I previously thought was pretty close to done. problem is, the needle is now at 4th clip, and there may be a little bitty hint left of a surge, so I was thinking about upping the main because the needle is now so high.

Here is the thing I need clarification on... I know we are supposed to work from the Main on down, and only change one setting at a time, BUT if I increase my main, but my needle is still at 4th clip, I'm pretty sure mid will be WAYYYY rich. Even though I would be only testing the main, would the needle still influence my readings, or is there a "reset point" for the needle?

[HKr1]

Just craking the throttle/light cruise is the pilot jet.

[headshrink]

Just put in the next Jet, should I lower the needle to a certain point, or leave it for now?

[Felipe the Ant]

Switching to a bigger main makes the mid range richer too if you don't lower the needle. I can't say how much it will affect it though in your case. But I'd say if you know it makes the bike run better go for it since you'll be riding it while you test it I'm guessing. Just remember that you have to find the right main first before a lot of fine tuning.

[HKr1]

Originally Posted by headshrink

Just put in the next Jet, should I lower the needle to a certain point, or leave it for now?

This is a nice read if you havent seen it before


http://www.motorcyclecruiser.com/tec...n/viewall.html

[headshrink]

I've read a lot, but don't think I saw that one.... will read that one tonight. Thanks

[headshrink]

OK, I'm reading the article, and so far it makes sense, but there is one thing I cannot reconcile. They say, because the effect is cumulative, start at the mixture screws, and work up to the mains. This intuitively makes sense, but we here, and the FP instructions go in reverse order, which I never understood, but complied with. Now I'm really confused, just when I thought I almost had it down.... which way is it?