ok installed Scream'n Eagle full pipes and I have a Scream'n Eagle air filter. didn't drill holes in the cover. Carb has 48 slow jet,2 washers under the needle,stock main 190....'05 Softail. Bike runs great. No cough, backfire nothing. got bike up to tempclean the plugs and did a 3.5 mile run not over 1/2 throttle,shut the bike down and checked plugs. Plugs looked very clean.No ring around the top thread where strap attaches. is this still too lean ? do I need to drive longer to get a better reading ?

Jim

 

I had similar results attempting the same test. Sounds like these tests worked better with the old leaded gas.

I'm thinking you need to go off throttle response and engine behavior during different senarios like described hereorhere.

 

Thank you. It's so confusing, how can you have a "tan" look on the plug when the only way youget that is after mileage. Then if the plugs show tan it can be due to using the choke.