[Spridgets] Rejetting carbs for high altitude

JLC breton48 at live.com
Mon Mar 23 12:33:06 MST 2009


Thanks to Roan Soave and WeslakeMonza1330 for replying...

I could not remember if the ignition had to be retarded or advanced for high
altitude... Could you explain to me why it has to be advanced? I am running
at 25 degrees advanced at idle, 35 at 4000-45000 rpm. I'll try 28 and 38. 

I know it's running too rich because I can see the "black soot" from the
side exhaust on the rear left fender! Did not used to do that... in fact,
the original setting by the engine rebuilder was on the lean side, and I
should have left it there. I had the car dynoed in San Diego, and it was
running somewhat rich after that, even at sea level. According to the dyno
graph, the air/fuel ratio varied from a low 11 to 1 at 3000 rpm to a high
14.4 at 2000 rpm - it was 13.1 at 6297 (max power with 115 hp at rear
wheels).

I am running NGK BCP 6ES plugs - will try two grades hooter for the same
plug.

I will buy an airflow meter... I can use it on another car too. Any
suggestions for a good one at a reasonable price?

Thanks again,

JLC


More information about the Spridgets mailing list