[honda nut]

I installed a K&N filter with a HMF muffler and Dyno jet. I turned the air/fuel screw out 2 1/2 turns. I checked the spark plug and it was the color of a brown paper bag.

The muffler was louder than I wanted so I put the stock back on. I checked the spark plug and it is black, but I have great power and the throttle is very peppy.

Should I re-adjust the air/fuel screw to get back to the brown color on the spark plug or leave it alone. Does the black on the plug indicate too rich? Will this hurt the engine to run it this way?

If I should adjust the screw, which way do I turn it to lean it up and am I still looking for the brown paper bag color??????

 

[IDigem1]

Now your bike is a lil rich . no biggy , but have you run the bike throughout the whole engine range RPM that screw is only one fuel circuit out of 3 rich better then lean , however have you tried the quiet core??? really cuts the noise ..i love the extra power with pipe !!! . Run your bike WOT under load then kill the engine coast . pull ur plug . that is the important reading