Need some advice about jetting for my '02, the header pipe is blue down to almost the bend. The engine is running the following, stage 1 cam, K+N drop in filter, drilled out baffle sporty muffler, ported exhaust port, 1/2 whie spacer, 50 pilot jet and 155 main jet and a  3 degree spark advance.
 I've been running the engine in the upper RPM range, over 4K to break in the new cam and try to get the top end carb adjustment right. Even with the 155 main the pipe is still a deep rich blue color.
 The engine is running raped ape strong and the cam has made a major improvement but it seems to be running on the lean side at the higher RPM's. I'm getting pops and backfires on throttle backs at speed.
 Is it possible to go up another jet size on the main, maybe a 157.5 and do they make one that size?
 Would removing the white spacer completely help in the mid range or should I drop it down to 1/3 of the spacer?
Thanks
Ed

I'm not removing the blue after every ride, it just seems that the bike could use a little more fuel.  I tend to tune my toys a little rich, just something I've always done.  The blueing has increased as I ride and is almost all the way down to the bend going to the muffler. Seems a bit lean to me, I'll play around with the carb, a 155 main seems to be what is recommended for my set up but my gut is to go bigger. I'll richen up the midrange by reducing the white spacer even more.

 The spark advance was pretty simple, I had to replace the left side cover and while in there I slotted the mounting holes on the ignition sensor and moved it about 3/8 of an inch counter clockwise on the cover. If I had gone any further the mounting screws wouldn't of been able to hold the sensor onto the cover.

 I've a degree wheel from back when I built gokart motors and when mated up to the crank it showed about 3 degrees advance on the ignition. Kinda rough but it gave another useable 200- 300 rpm top end and a bit more grunt out of the hole.

I'm starting to think that's why the exhaust is running hot, more spark advance heats things up.

Used to tweek inline six cylinder car engines like this with spark advance at the distrubitor and just thought it was worth a try. So far I've been happy with it.

 Bet it would be possible to advance the engine a lot more before dentonation but a custom bracket for the ignition sensor would need to be made. Still working on that in my head

When I bought the Guzzi in Houston and rode it home to Longview, the pipes were blue before I had 30 miles on it.. Who cares if it's blue? You don't really think that the guy who put headers on his hot rod cares about them turning blue.. If it's running good,ride it,,, If it's lean, then jets are the answer, read some of the carb tuning threads,, they will tell you Exactly what to look for to decide if you have a lean or rich spot.

If that bike puts a smile in your heart when you're picking a line thru a curve and leaning into the gas and accelerating out, checking the Speedo to see if your exit speed is getting better, then what someone else SEES when they look at your bike means exactly Nothing... If riding it fills you up with the joy I got when I was riding,how it looks is as important as the color of the sheets on the bed. My wife asked me what color sheets I wanted.. I
told her to get what suits her.. I generally sleep in the dark,with my eyes shut... any color works fine, but, I do think I make better time thru the twisties in my dreams on red sheets.

Lose the chrome and paint it black, Problem solved.