to rich on bottom ..it should rev up a little bit longer coming in off running on the track ..its just something you have to be able to hear ....

run 6-8 laps get good and warmed up ...bring it in pull the body ...rev it up a couple of times to clear it out ...pinch the fuel line going to the hsn really hard cut all the fuel off .....it will do one of three things probably ...instantly stall without reving up = to lean on lsn
rev way up before it dies = to rich on bottom
rev just slightly up before it dies = just about right and in the ball park
once you do it a few times you can get the feel for it without killing the motor ...then adjust re-rev and try again

for the idle question ...you should not have to play much with your idle setting using a different restrictor ...as stated above ...but you will have to re-tune your motor ...i wouldnt suggest limiting the throttle to compinsate for some thing ....i limit my throttle on all engines to about 1 mm before it clears the carb ....that way im not pulling farther than i need to ...hope that made sense ...alan burton had told me that drake will run his throttle to about 1 mm past full open when running a restrictor ...he could tell me why ...only that he does it so alan does it ......anybody see the benifit in that