wrong it is #150.... look again....

 

Yeah guys, it is #150.......better to have the carb actually in front of me I guess. All valid points mentiomed above. That #342 diaphragm can be hard to seat properly and get pinched. Did that once, and it's about $40 to replace.

 

wow now im confused.
had this carb on my sporty,(diferent jets), and always adjusted the screw at the bottom. i thought this adjusts the fuel to air mixture at idle.
the screw at the cable bracket 354 or 150 adjusts the tension in the throttle cable. i always adjusted that so theres a sight play in the cable, while resting on the stop.
then adjusted the fuel to air mixture screw (the bottom), to set my idle.
whats right?

 

The tension in the cable (or cables if you have an idle cable) should be done at the throttle end up on the bars. The actual throttle cable should have "play" in it while your setting your idle speed using Screw #150. I would probably set the idle mix screw (bottom of carb) to about 2 turns out from bottomed as a base setting and try that.

And speaking of carbs, I can't beleive how much S&S carbs jumped in price over the last few years. I bought a super-e complete kit not long ago for like $280. Now they are $450.

 

your method is incorrect. You adjust the cable tension from the adjustors at your throttle(1/8" of play). You adjust idle speed at #150 screw and idle AFR from the bottom screw... The AFR needle should cause the bike to die when turned all the way in. If it is not, You either have too large a low speed jet, or the idle is set way too High at screw #150. Set your idle screw(150) so the engine dies when the AFR screw is turned all the way in. Do these settings once the bike is warmed up. Now turn out the AFR screw about 2.5 turns and restart the bike. From here, you can adjust AFR for smoothest idle. It takes a good ear to adjust this properly. One other thing, when making these adjustments make sure the cables are not too tight at the throttle. If you can't get a good idle, there is now a chance that you have an intake leak and need to look into that. Once all adjusted, you can back the idle screw(150) off to get the lower idle if it is a little too high. The more you back off the idle screw the tighter the throttle cables get. Getting this all correct takes some experience and a good ear to be able to hear the changes in the bike while at idle. You get the Cv dialed in and you will not find the need to waste money on an S&S carb.

 

Like several people have said - part #150 in the diagram is the idle speed adjustment. However, if turning the AFR screw all the way closed or all the way open does not effect the way it runs at all, I suspect either improper jetting, float adjustment, or possibly an air leak.

 

Are you running the plumber intake? They can be a big problem.

 

what type of adapter are you using?

it sounds like an air leak for sure, get one of those propane torches wit hthe 2lb blue tanks start teh bike up and hold the torch on but UNLIT close ot the seal points where the adapter meets the carb, the adapter meets the manifold, and where the manifold meets the heads. if there is even the smallest leak the propane gas ill be sucked in and change your idle rpm noticabley letting you know where the leak is

 

thanks guys...im going to check it out tonite.

 

for mountign a CV to the older type manifolds the mikuni flange adapter is teh best sealing one