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I have a 1975 50HP Mercury 500 with 2 type KA carburetors. The motor was running fine , and quit when tanks were switched on a 20 mile trip. Couldn't get restarted. Rebuilt the 2 carburetors and fuel pump. Motor ran about 10minutes on a hose; quit and wouldn't restart. Water pump good, perfect compression, strong spark.
In checking carburetor butterflies I found that when the fast idle lever was moved from minimum to maximum there was ONLY spark advance and the carburetor butterflies were still closed. Is this correct?
Wanted to resolve this question before removing the carburetors and disassembling them again. These particular carburetors have idle tubes with very small passages and holes; that could possibly still be clogged.
In checking carburetor butterflies I found that when the fast idle lever was moved from minimum to maximum there was ONLY spark advance and the carburetor butterflies were still closed. Is this correct?
Wanted to resolve this question before removing the carburetors and disassembling them again. These particular carburetors have idle tubes with very small passages and holes; that could possibly still be clogged.
