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2.2 Weber Jetting

Fuel System

Vehicle Information: Model: 911T; Year: 1970; Body Type: Coupe; Engine (type, size, modifications): 2.2 'T' engine, 'S' pistons, 'E' cams, Webers; Total Mileage: 112,000;

Can you give me a check on my carb setup? I have a 1970 2.2 "T" which has been rebuilt with "S" pistons and "E" cams. The Zeniths have been changed to Webers. It has been in place for a while and generally runs and idles well, other than a slight bog under sudden acceleration. But I have never been sure that I have the optimum setup in the Webers as far as jetting, etc., and would like your opinion. Further, people following me on club events have said they see black smoke under acceleration, indicating that I am running too rich, but the research I have done including responses from you to other questions on this indicate to me that I am in a lean to normal range for most of the settings. As you know, it's very hard for the lay person to find good information or determine the specifics for Webers in a given application. For example, my main jets are 125's, I've seen where you recommended a much richer 145 to someone running a modified 2.2. My idle jets currently are 55's, I have seen where you have recommended from a 50-52 for one person all the way up to a 60 for someone else with a modified 2.2 engine. I have F26 emulsion tubes, air corrector jets of 180 (you have recommended both 180 and 185's in the past), idle air bleeds at 110 and accelerator pump jets at 50. When I was first trying to get the Webers running, a mechanic told me part of my problems were with the stock "T" manifolds being too small with the other modifications to the engine, so he had those enlarged at a machine shop. I don't know offhand by how much, but it did run much better after he did that and set up the Webers as described above. I'm getting ready to take them off and do a complete cleaning and inspection, with new gaskets, o-rings etc. and figure this is the time to make any changes I might need. Last time I did this, float levels and accelerator pump volumes were spot on, but I will check those again as well. Also, is it true the venturis would have been 27mm for a "T" and 30mm for an "S" - and with a motor that's a bit of both, where should I place my bet with those? Any thoughts you have on the optimum for all of these settings is greatly appreciated.

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