Screw Info
The small black screw is the idle
Turn it anti clockwise to stop the wheels free spinning - normally the carb is good at a 2mm opening, clockwise if the revs drop and it stalls
The bigger screw is the High Speed Needle (HSN).
Basic Tuning
Tune in order, make sure the car is at its base settings - the setting u broke it in with. It should be very rich (boggy/lots of smoke/ possible stall) at these settings and performance poor.
1. High Speed Needle
Turn the HSN clockwise in a 1/8 increment and drive down a straight each time you'll see a small increase in performance (and a good trail of smoke), keep doing it until:
A: There’s little or no smoke from the exhaust
or
B: The cars gets slower at full throttle (down a straight) or stalls at full throttle
at this point turn anti clockwise 1/8, its still no good turn another 1/8 that will be enough
Un-tuned HSN Symptoms:
Too Rich - Lots of smoke/slow-poor performance/stall/groggy sound to the engine - Turn clockwise
To Lean - Little or no smoke/very fast/loss in performance at full throttle or stall - Turn anti clockwise
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2. Low Speed Needle
Do the same with the LSN, but only very small increments at a time, you are looking for a fast + smooth acceleration with some smoke, a steady idle with some smoke and a bit of un-burnt fuel won't hurt
Note: it takes time for the LSN adjustments to be visible, it helps to accelerate at full throttle for 5 seconds then brake - repeat until u see the change then carry on making adjustment.
If it stalls, stutters with high revs / no smoke on acceleration then turn anti clockwise 1/8, if no good unscrew another 1/8 - this should be enough
Un-tuned LSN Symptoms:
Too Rich - Lots of smoke and un-burnt fuel at idle/slow acceleration/stall
Too Lean - little or no smoke on acceleration/immediate stall on throttle/high engine revs
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3. Idle Screw
Your idle may be affected after these changes, make adjustments SMALL INCREMENTS at a time,
Turn anti clockwise if it runs too fast at idle - wheels spin with no throttle
Turn clockwise if its too slow - e.g. revs drop then stall, stalls on throttle
Once tuned your car should have a fast smooth acceleration, impressive top speed, steady idle and ALWAYS a good trail of smoke
Wrote By Dazzi Edited By Me