Re: Merc 115 Carb Rebuild
Danny, a service manual will help, but the carbs are real simple. I assume those are the side bowl carbs? Clean and blow out each passage and jet. Install all new gaskets. Inspect the floats. The orig were foam and can disolve. The replacements are hard plastic and can crack. Replace all that need it. It also makes sense to replace inlet needle and seats. Invert the carb cover and bend the carb levers until they sit parallel with the carb cover. Make sure the little spring on top of the floats is intact.
Initial idle mixture setting is 1-1/2 turns out from lightly seated. Adjust for smoothest and fastest idle in the water and then richen the top carb 1/8 turn and test acceleration. Most of the time the carbs will be set too lean, so continue to richen the carbs 1/8 turn at a time, top carb, followed by mid-carb and then bottom carb, testing after each adjustment. When you achieve smooth acceleration and reasonable idle (800-950 RPM), you have achieved success.
