Groundman

Once you adjust the HSN to correct setting will your idle have to be adjusted every time. I was also told that once the HSN is set, you should richen the LSN a quarter of a turn and the motor should be set. Is this correct?

Anthoop

No that's not correct groundman,go to schumacher forum/nitro trucks/carb tuning i'm sure you'll find all the info. you'll need!

ProRCRacer88

You should never have to even touch the LSN, if it needs to be adjusted it should be adjusted by a skillful engine tuner.

Schumacher RC Superstore

The original setting for the low speed needle is flush with the base of the chamfer on the screw. Leave it there. The low speed is affected by the high speed adjustments so you should only need to reset idle if need be when changing your high speed settings for the daily conditions.

Anthoop

There are many methods people use to set their LSN. For me- I typically clear out the engine by doing a high speed run, bring the truck in and allow it to idle, then watch and see how it responds at idle speeds. If the idle speed drops right away or slowly drops within a few seconds ( or if temperatures start to drop too fast) = the LSN is too rich allowing too much fuel through which is loading up the engine lowering it's RPM. If it starts to climb in RPM ( or if temperatures also start to climb) then it's set too lean. Adjustments should be made at hourly incriments with a high speed run in between each adjustment to clear out the engine. Once I get the engine to idle for at least 20 seconds or so without excessive load up, once again, I'll clear out the engine, bring it in and idle the engine for 5-10 seconds- then hit the throttle to watch how it accellerates. It should accellerate smoothly and powerfully from idle all the way to max RPM's with a nice healthy smoke trail leaving the exhaust. Even finer LSN adjustments can made in even smaller incriments to fine tune this setting. Once your satisfied with your overall performance- you can adjust the idle speed ( if neccesary) by using the Idle stop screw. This basically adjusts how far the carb's slide barrel will close. The LSN will affect the idle speed/quality if it's not set correctly- so it is important you're able to achieve and hold a steady idle at the manufactures suggested setting (usually at around 2mm) before making it's final adjustment. Remember- you're not entering a contest which engine can hold the lowest idle speed so just set it to where it's comfortably below clutch engagement to prevent premature clutch wear.
Info from http://www.racing-cars.com/