Most carburetor manufacturers like Carter, Rochester, Stromberg, Zenith, etc. stopped using adjustable main jets back in the late 1930's or early 40's. Think of all the research and development money they could have saved by simply continuing to use technology that existed back when engines had 6:1 compression ratios, Babbit bearings on the crankshaft, and needed to be rebuilt every 30,000 miles! How does the power enrichment system get adjusted for such things as automatic or standard transmissions, different rear axle ratios, and other variables that aren't directly affected by either idle or main jet adjustments? The "one size fits none" approach has been tried repeatedly, and failed every time. Maybe this time it will be different. I suppose some people will be willing to accept mediocre performance from a universal carburetor because they don't know any better. Growing up eating 30% fat content hamburger is OK as long as somebody never gets served a prime quality steak, also.
I wonder if the average purchaser of one of these carburetors will have a 4-gas exhaust analyzer and a chassis dynamometer to help get those adjustments done correctly?
Jerry
