20 hp 2 stroke mercury 1998 I'm have a gas problem. when i start it, it idles fine but once i give it gas beyond idle speed it cuts off . Starts again with first pull. no choke needed. it runs on low speed for miles, speed it up and will cut off.
It's fuel system related.
Start with checking all of your fuel lines. Make the sure the bulb is staying firm. Check all of the fuel fitting for cracks.
Do you have a fuel water seperator?
Next would be carbs.
If you are running ethanol fuel, more than likely if not guaranteed your fuel lines aren't rated for it. It eats them from the inside out. The fuel going into the engine will have a milky appearance.
those get replaced with ethanol rated MARINE GRADE fuel line. Not Auto Zone fuel line.
Marine fuel line has a built in fire retardant.
Mine was having a similar issue at first startup this year. Had to drain out ~100 bucks worth of "milky" fuel and replace with fresh. And just stick to buying ethanol free fuel - Here's a link to a database of stations that carry ethanol-free.
that milky crud will varnish and clog up the high speed jets in the carb and clog ports that allow fuel to react to changes in the pressure when accelerating. Idle circuit will work fine but hit the gas and she dies. You may have to rebuild the carb with a good long soaking in the cleaner and blowing out properly to ever get it "right".
this has been such good informTION. Thanks for all your insight and help with understanding my dilema. It was right on..Now I can clean and run with safety in mine. Always file a float plan. Call on and off the water. Makes Momma let you go again.
It would still be a good idea to change the fuel line to ethanol rated line because then you are covered. You might be in a situation to take what's offered at some point which may be ethanol fuel. And ethanol free fuel is more expensive.
Fuel expense is what is feeding yak sales, not the global warming greenies crowd.