ORIGINAL: RCtruckRacer

Neither the amount of visible exhaust, nor the temperature are true indications of a correct tune.

There is a point at which the air fuel mixture will allow an engine to be able to obtain a maximum of RPM's. The sweet spot is generally regarded as being slightly rich from this point. That is the only true indication of a proper tune. Being slightly rich from the point at which an engine will reach its max RPM's cannot be judged by temperature or the amount of smoke coming out the stinger.

It is SO easy to reach this point. All you have to do is:

1) Start out with rich settings. If you are unsure how to go about this, an easy way is to start with stock needle settings. The factories always set them rich for break ins.
2) Warm up the engine. Try not to hammer the throttle too much while its still bone cold, but slowly work your way up to a couple WOT runs.
3) Now that the engine is warmed up (1/2 tank is good), do a couple WOT runs in front of you and pay attention to the pitch of your engine. The higher the pitch, the more RPM's its doing.
4) Now lean out the HSN by 1 hour increments (30 degrees, 1/12 of a full circle etc) and continue to do some WOT runs in front of you. The engine's max RPM's should continue to go up each and every time you lean out the HSN by those 1 hour changes. If it doesn't, you have reached the top end and need to richen by an hour. Make sure that you do not continue to lean out the HSN after max RPM's have been reached. You will damage the engine.

Congratulations, you just found the sweet spot. Now, if you notice that the car/truck bogs a bit at take off, lean out the LSN (again 1 hr increments) until it will take off at the touch of the trigger.
And you're done. At this point I like to temp the engine to get a baseline reading for the day.

This is a simple and fool proof method of tuning that everyone can do. Regardless of experience.