Adjusting gas/Air Mixture

[tbettes]

After searching this forum I feel lucky my problem is small compared to many. When the water heater lights, the exhaust has some amount of carbon in it, enough to create a trail up the side a few inches after a while. I have tried adjusting the air mix portion of the tube going in but since I am not sure how or what direction to move it, I thought it would be wise to seek the wisdom of the many more experienced people here. How do I adjust the mixture?

Thanks
Tom

[tbettes]

I was told by a friend who seems to understand and know everything mechanical that I should increase the air content until the flame has no yellow, only blue. I maximized the air and the flame is almost all blue except at the end. The carbon has almost completely stopped. Hopefully this will help someone.

Tom

[raveson]

Make a note to check your other gas appliences. The same blue flame applies.