Anybody done one of these? I've got one sitting on the shelf here, it's raining and I have the next couple days off from work so I'm thinking about doing it. I'm not worried about the difficulty, just if it's worth the effort. Does adjusting the idle mixture help that much? What does it help? My hope is that I can eliminate the decell backfire and smooth the transition between jets.

 

Easy to install and very useful. Adjusting the air fuel is what its all about.

 

I take that as a yes!
Maybe tonite, after my helpers go to bed....

 

air mixture screw on bottom of fuel bowl
just remember the number of turns

 

Remeber not to crank on any knurled ***** too hard or you'll screw up the post seal. The best mixture (I prefer a 13.2-13.5 AFR) is dependent on RPM, intake speed, air density, air/engine temperature, and engine load. Basic operation: the idle mixture screw is for the idle circuit (0-1/4 throttle) to the transfer circuit (small holes by the butterfly plate) to the needle jet/jet needle (1/4-3/4 throttle) at which point primary jetting is done by the main jetting (3/4-WOT). Changing the idle will affect mostly idle and a small degree on the following circuits. Better to either hook up to exhaust gas analyzer (EGA) or better yet, perform 4th gear roll-ons for main jet adjust and a cruise test for the needle on a dyno to tune [takes about 4 runs or 1 hour].

 

robzuc, Thanks for the info but I'm hoping to get it good enough with my ears, nose and seat of the pants feel.

Got it on early this evening. since my manual does not detail the idle drop procedure for the sporty I just tried how it has been done on other bikes I've owned. Go slowly richer until your idle gets rough or drops then go lean half a turn. Idle is smooth as silk and smells good. Did a roll on in first- third to redline and it accels smooth, decell backfire is almost completely gone. The only flaw is a quick throttle blib from idle exhibits hesitation that was not there before. I can hammer it from a near idle roll on in first and there is no hesitation so this is a little puzzling. Over the next couple days I'll go a little leaner and a little richer and take notes.....