Author Topic: Running Lean ??  (Read 919 times)

Offline Roy

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Running Lean ??
« on: August 20, 2023, 01:12:38 PM »
Quadrajet Number 17085213......Knowing that my qjet was the wrong one for my application, I bought a kit from Cliff a few years ago requesting the correct jets and metering rods for my 1981 Corvette 350 engine with a earlier carb and distributor.. The kit was supplied with .073 primary jets and 50C primary metering rods and DP secondary rods, and a new power piston spring. After aproximately 2000 miles after rebuilding the carb, I pulled the spark plugs and found them snow white with no color at all, even down in the insulator. I'm old school and always looked for a light tan on the insulator. Has the new ethanol gasoline changed plug colors or am I running lean. (The car runs exceptional well). My previous experience would tell me that larger jets are required, but I am waiting for someones expertice before changing them.

Offline Cliff Ruggles

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Re: Running Lean ??
« Reply #1 on: August 21, 2023, 10:00:40 PM »
We tune for performance, not spark plug color.  If it works well don't touch the carb anyplace.  It is impossible to read plugs on this new fuel anyhow.  If it were "lean" you'd have hesitation, stumble, bog, "flat" on acceleration, surging, etc.....