adamkerrnz

hello,

I was doing some high speed test running on my street today and i noticed that when i stop after the engine was doing a high speed run, the engine woul rev quite a bit higher than idle then die back down to idle revs after about 3 seconds. is this normal or can someone tell me something to adjust on my carb that can fix this.

InitialD

Try lowering the idle needle and at the same time lean the low speed needle (LSN) in 5 minute movements till you get a stable idle.

AMGRacer

It is somewhat normal if you are doing a long high speed run, turning around and doing another long high speed run, continue until you run out fuel. You need to richen up the top end needle on the motor to handle repeated long (I am talking over 60m long) high speed runs. This type of thing does not happen on the track in general and you need to tune the motor slightly differently.

adamkerrnz

i think ill try InitalD's method, thanks for the help

fathead

I think you should do as AMGRacer suggested and richen up your main (highspeed) needle as it sounds like your motor is leaning up after an extended high speed run which will cause the high idle speed for a moment after you stop

Jamie Corrado

iTrader: (17)

If your clutch is set up proper and you have good low end snap don't touch the low end needle just yet. Try to lower the idle first and see if you get a consistant idle speed. Assuming your linkages and endpoint on your radio are set properly. If you are still getting a high idle then move onto richening up the low end.

InitialD

Yes, that symptom sounds like the main high speed needle leaning out but remember that if you have the idle open up too big and the low speed needle too rich, you'll falsely create that high speed needle leaning out situation.