I have cleaned and rebuilt my 94 carb on stock .060 59ab. Engine starts right up and idles great. It has the correct 7.5 power valve and 51 jets. It starts to stumble with higher rpms, ( 2000 and above ). I have taken it apart and check all the holes, and cleaned it again and again. No vacuum leaks. I can send it somewhere to get it rebuilt, but I believe I did a good job on the rebuild. I'm lost!!!! Any help from carb guys would be greatly appreciated. Thanks Ron
Are you sure it's the carb and not an ignition problem? Does it feel like it's starving for gas? I seem to remember something about the power valve gasket in some rebuild kits not being correct. If you need to check with the experts go to the fordbarn.com and ask there.
Five years ago I ran into the same problem (high rpm hesitation) and twice rebuilt my 94’s only to find it was the Resister this time and not the power valves. Frustrating.
What kit did you use on that rebuild? Vintage Speed has the correct PV for those carbs. Compare the old to the one you used. I had used NAPA kits in the past and every one of them had the wrong PV. They do not seal correctly.
Rottenron, post this on "The Ford Barn" too. Lot of flathead gurus there too. H A M B E R S & BARNERS are the best.
It could be an ignition problem. Weak point springs is a possibility as well as point gap. Spark plug gap or plugs themselves could do that. Compression pressure increases as speed increases. Weak plugs can misfire under high pressure. We used to have an old Champion plug cleaner/tester that allowed you to actually see how well the plug fired under pressure. It's surprising how many failed the test.
It doesn't sound like a carburetor problem, but if it is, a possible place to look would be the mounting gasket. Some folks try to use the Stromberg mounting gasket with a Holley; but they are different. The Stromberg gasket MAY be used if the power valve hole is punched in the gasket. Most of the Holley AA-1 carbs (including the 59) require the hole. Jon.
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