I have a 1971 Johnson 50HP that was given to me on a 14' boat. It hasnt run in a few years, the previous owner had the same problem that Im having. Its runs great on muffs, as soon as it hits water the idle drops drastically. It will not idle unless the the lever is in the start position, and is very hard starting. When Im on the throttle on the lake it sounds ok but will not get close to full speed or RPMS and uses a lot more gas than I think it should. 5 gallons in about an 8 mile run. It has good compression, 125 psi both cylinders. I have cleaned and rebuilt the carbs (twice), just to make sure I didnt miss anything the first time. The reeds appear to be OK. Changed the head gasket, fuel line and coils, and de-carbed once. It does not overheat. I have a lot of 2 stroke experience with motorcycles but not boats. The owner of a local marina has suggested possibly the stator. Im at my wits end, any suggestions would be helpful. I have a service manual, the carb linkage and timing seems to be correct.