One area where even an experienced mechanic can have issues is the setting of the float in a carburetor.
Just had a regular customer on a different make of car call with flooding issues. This guy is an absolute stickler for doing things "by the book".
So when he called, we talked about several possibilities, as the carburetor he had came from a commercial rebuilder, and he thought possibly the floats were incorrect (it was a Carter AFB, and Carter used 4 different floats, each with a different buoyancy in the AFB carbs). He had taken the carb apart, and checked all the settings against the book.
Once we determined that he did indeed have the correct floats, we started discussing other possibilities, and float setting became the topic. His factory shop manual (printed months prior to the manufacture of the vehicle) stated 7/32 float setting. I pulled the current Carter prints, and a float setting of 5/16 was recommended. So started checking various generation prints for this carburetor, and one of them stated TWO different settings:
(1) 7/32 for steel fuel needles
(2) 5/16 for neopreme fuel needles
This particular carburetor was built during the transition from steel to neopreme tipped needles.
Since the float exerts pressure on the fuel valve, the neopreme tip is slightly depressed thus raising the fuel level in the bowl above the desired height, if the specification for the steel needle is used.
It becomes apparant how critical this setting when 3/32 of an inch can cause flooding.
Jon.
