Taking Srinraths advice, I got 40 pilots, 145 mains, 1 #4 washer on each needle, and 3 turns out on the mixture screw

This is for the K N Lunchbox filter.

Now how do I tell if it's rich or learn, or if it's perfect?  I'm *thinking* it may be a bit rich, I get an occasional backfire when revving it up.

I'm thinking about backing down to 2 and 1/2 turns out on the mixture screws..  Is it possible to adjust them without taking the carbs back out again?

Thanks for any advice guys!  And thanks so much for all the information thus far!

Yes, you can adjust the screws using the tip off of one of those removable-tip screwdrivers.

thanks for the tip, but my mixture screws were really tight, and took a lot of effort to move.. so there's no way I could just use my fingers to turn the screw with a flat head tip... so I may just have to pull the carbs out again..

so how can I tell if i'm running perfect/lean/rich?

http://cgi.stanford.edu/~sanjayd/gs500/Upgrades/Rejetting-LeanOrRich?