Air Fuel Mixture Xl1200 Low

[Mad Man]

Recently I had some work done on my bike and rejeted the carb. Stock jets are 40mm and the next step up is 44mm jets. The bike has run fine but now I have too rich of a mixture in spite of having a Screaming Eagle air intake/filter, and new slip on after market mufflers. I kept the stock pipes due to cost and planned to purchase some new high flow exaust manifolds later.
Looking in my service manual, I cannot find how to adjust the jets for LEANING OUT THE MIXTURE. The goal that I hope to achieve is to increase the performance. NOTE: THIS IS A STOCK HD CARB! My spark plugs are showing gas fouling, and hard starting due to xcessive fuel.
I am not ready to go to a full stage 1 set up with machined heads, valves, cams... ect. I just need to know how to adjust the fuel air mix & lean it out. PLEASE ADVISE... Thank's

[Dave63]

Originally Posted by Mad Man

Recently I had some work done on my bike and rejeted the carb. Stock jets are 40mm and the next step up is 44mm jets. The bike has run fine but now I have too rich of a mixture in spite of having a Screaming Eagle air intake/filter, and new slip on after market mufflers. I kept the stock pipes due to cost and planned to purchase some new high flow exaust manifolds later.
Looking in my service manual, I cannot find how to adjust the jets for LEANING OUT THE MIXTURE. The goal that I hope to achieve is to increase the performance. NOTE: THIS IS A STOCK HD CARB! My spark plugs are showing gas fouling, and hard starting due to xcessive fuel.
I am not ready to go to a full stage 1 set up with machined heads, valves, cams... ect. I just need to know how to adjust the fuel air mix & lean it out. PLEASE ADVISE... Thank's

Your slow jet is now.044" stock....not 44mm. 44mm is about over 1.75" in diameter, which would certainly explain the richness.....

You can lean your a/f mixture by turing the a/f screw under the carb, towards the center of the cylinders. It has to be uncapped first.

If you're running that rich WITHOUT after a slow jet change, (.044 in it now) then you have a dirt issue in your needle/seat, or a float level issue. The other thing I'd look at is the slow jet was never tightened correctly and is now loose.