ColorTune - CANNOT GET COBALT BLUE!!!

Ok, so the carbs on my 85 XJ700N are as clean as can be, the plugs are brand new (NGK), the petcock is brand new, new fuel line and in-line fuel filter, the air filter is in correctly and even the chrome plastic air box covers are on! However, I cannot get a blue spark when I install the Colortune plug. When I rev the engine up to 3500 RPM, I get a slight blueish tint to the spark, but that's inconsistent, at best. WHAT GIVES?!?

 

At 3500 RPM you are off the idle circuit so what you see there doesn't matter. The Colortune is to be used at about 1100 RPM. What color do you get with the bike idling? If it is white to a light blue then check for air leaks at the airbox and intakes. If all you see is yellow then the choke circuit may be slightly on. Need to know what you are seeing and not what you aren't.

 

At what RPM is a 700 when you come Off-Idle?

That little window of Transition ... from Idle to Off-Idle is still deppendent on the Pilot Jet Fuel supplied for a moment.

Even so, as the Bike transitions from Off-Idle to Main's ... The Pilot Circuit is still supplying Fuel to the transition Mixture. There ought to be someplace in-there, where you'd find the opportunity to dial-in the Pilot Jet Fuel supplied to get a Bluish indication that the Mixture, within that window, is the best that can be Dialed-in by adjusting the Pilot Mixture Screw.

 

BlueMaxim, the color is actually light orange, no matter where I set the pilot screw. Could it possibly be that one or more of the air jets are installed incorrectly?

 

Correct Air Jet Placement.

I think I triple-checked this set-up

 

If it stays orange then it is rich. Check the choke and make sure it is off and not held open a little by a tight cable. Could also be a high fuel level in the carbs.