[Spridgets] Rejetting carbs for high altitude

Robert E. Shlafer pilotrob at webtv.net
Mon Mar 30 11:54:58 MST 2009


"He told me if I cannot get the Lotus to run properly, he'll set it up"

Excellent, Jacques.

BTW, I believe Ron S. mentioned lower octane fuel. 

The first thing I would do is drain the fuel tank and go with the lower octane fuel.

If still "rich".....

I would than advance the timing no more than 3 degrees or so, then re-set the idle mixture/idle speed and give it a whirl.

If still rich, but no "pinging" on acceleration, I might go another 2 degrees for a total of 5 degrees advanced from sea
level setting.....re-set idle mix/speed and try again.

(If the car starts hesitating (wants to quit) just off-idle, bring the ignition back 2 degrees, install the warmer plugs....and try again.

Still too rich? Go to the leaner mains and on and on in logical order.

The lower octane gas and/or advanced timing with eat up excess CO (richness) throughout the whole range and  this may be all you'll need, If not, I would then go to (ONE step up) a WARMER (not colder) plug. Remember, you are correcting for LOWER compression pressure (REDUCED effective CR) than on to leaner main jets if needed.

In the end you have the friendly shop to assist! Glad you found same. There hadda be somebody around advising the natives and most certainly those newer to the neighborhood from the "flatlands"!! :)

Cap'n. Bob      '60 :{)


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