Colortune

[Guest]

Just wondering if anyone had experience using Morgan color tune to see the color of the spark and adjust the fuel mixture from there? I just bought one because I wanted to try to really dial in my carbs.
Often though I when I back out on the pilot air screw it seems to do very little. (I have my fuel screw and air screw set to around the norm of 3/4 and 1 1/2 respectively) no matter what I do the always seem to run rich. I'm not sure if this is something other people have noticed. Do the bikes just run rich. Should I play around more with the pilot fuel screw?
Or was the Morgan colortune just a waste?

by the way the bike is a 1977 gs750 and yes I just adjusted my valves a few weeks ago and my carbs were cleaned at end of last season

[hannibal]

Did you bench sync the carbs off the bike then vacuum sync on the bike? Folks on here say the colortune works well on the VM carbs but I have yet to try it.

[Steve]

Yes, it should work very well with your VM carbs. If you are not seeing a difference, it's possible that there is something amiss in your carbs that is not actually changing something when you turn the screw. It's also possible that your fuel screws have been overtightened at one point and enlarged the hole. Try turning them in just a bit (1/8 turn?) then try turning your air screws to see if that makes a difference.

Except for the lower gas mileage and possible environmental concerns, I would rather have it running rich than lean.

.

[ttfraz]

Sorry for the delay
so I decided to take a look at the float needles and double check the inside of the carbs. Everything is up to spec inside but as I was opening up the airbox it seemed like gas was coming out of the carb body and into the airbox. I noticed it specifically on the number 2 carb but I can't say for sure weather it happened on the others.
Would this cause it to run rich? Any ideas why this would happen? I just had the petcock apart and everything looked fine when I put it back together but is there a good test to know for sire

[hannibal]

#2 counting from the left side under the clutch hand?

My float needles looked fine but I could feel a ridge with my fingernail. That was enough for them to leak. And yes that would certainly cause the bike to run rich.

[ttfraz]

Ya #2 from the left. There no rubber on the float needles right? Just brass to brass

[hannibal]

Yep.

Added for length