Richard - the YH carbs have a couple of issues that are not the fault of the carburetor:
(A) There are 4 distinct generations of the YH: (1) Corvette and early Nash; (2) marine applications 1956~1959; (3) marine applications 1960~1964 and turbo Corvair 1961~mid-1964; (4) applications mid-1964 and newer. EACH GENERATION HAS A DIFFERENT BOWL COVER GASKET. The generic commercial kit has two gaskets.
(B) Carter used spring-loaded needles and seats in the YH carbs to minimize flooding issues. Spring-loaded fuel valves cost approximately 8 times the cost of the solid fuel valve. Guess which valve is in the generic parts store kit.
The major issue with the YH is the diaphragm-type accelerator pump. There is no neopreme yet known to man that will survive deathanol and drying out. Those who drive the cars daily should see 2~3 years without having to rebuild the carbs. Those who drive them and then let the fuel evaporate from the bowl can expect to rebuild about every other time they start the engine.
Jon.
