An easy test for the float-level at idle, is to just clamp the fuel-line while the engine is idling. If the level is too high, the pull-over gets to be too easy and the engine idles rich,So you crank in the mixture screws to compensate. Then it may be lean at throttle tip in, and you get a hesitation when driving nice.So you fatten up the pump-shot and it goes away. You get away with this cuz you have a fluid coupling. But a car with a manual trans would not be so happy.
Any way, with the engine idling on the clamped line, very soon one of three things is gonna happen;.
1) the idle is gonna speed up, level off for a while, then slow down and shortly stall
2) the engine is gonna idle just fine for a bit, then slow and stall
3) the engine is immediately gonna begin slowing down and stall.
1) is rich, 2) is normal, 3) is lean
The carb was factory calibrated to operate properly on all circuits, with a designated float level. If the above test indicates that the float level wants to be changed, but the your carb is already at the proper float level, then something is wrong. You cannot wander too far from the manufacturers level without creating issues in the other circuits.............so this is more or less a diagnostic test. It's easy to do and fast.
Some combos don't mind the float level running a little lower.
Altitude can be a factor, but out here on the prairies, we average 950ft in all directions, for hundreds of miles,lol.
Make sure your secondaries are closed all the way, but not sticking.
If the throttle shaft flops around in the bushings, then the idle can be unstable.Make sure you're not inadvertently wearing yours out with a too-stiff spring. The cable and the spring should pull in in opposite directions,and in nearly a straight line.
