Reply To: lean sneeze

[Don]

Sounds like you tried a different carb which changed nothing, correct? Pretty much rules out carb issues….Except for carb synchronization…Are you sure the linkage is set up correctly and the butterfly is closing completely at idle? Just because the roller isn’t touch the carb linkage does not mean the butterfly is closing properly. Haven’t had too much experience with the 9.5s, but I do remember that cam/butterfly linkage is strange….Just like the rest of the engine I guess…I don’t know if there is a way to mess up the mag plate linkage on these engines that might cause the ignition timing to be overly retarded at idle/low speeds, check the throttle cam pickup setting.
I’m guessing you have just gotten this engine, but will ask if it ever ran OK for you? Sounds like you have already removed the powerhead and replaced both seals, I’m guessing that made no difference. You mention the reeds look OK, did you just peek at them or remove the leaf plate assembly? Remember there are two different intake gaskets, I’m not sure if it is possible to inadvertently swap them on this engine or not…If so, Using the carb gasket under the leaf plate assemble would create a crankcase leak between the two cylinders. A broken fuel pump diaphragm probably would have rendered the pump inoperative.
Any evidence of previous major work on this engine? Does it look like the crankcase has been split? New head gasket, or exhaust gaskets? Does it look like someone had been messing with the intake manifold?