Re: Question for Rodbolt
the 115 yamaha is about bullet proof and has a simple CDI ign with a movable timer base. the 02 johnson should be a carb motor and if it will run ok with the primer bulb being pumped it needs a fuel pump repair and or a fuel system vacum test. what your doing by using the primer is bypassing/assisting the engine fuel pump. if gas aint in the carbs it wont go. period. by squeezing the bulb your keeping the carb bowls full. actually DFI and EFI will work close to the same only they use a common fuel bowl known as a vapor seperator to draw fuel from for the high pressure pump/injector.<br />its all about the same no matter who makes it. it sucks,squeezes,bangs and blows. how many strokes it takes to do it is irrelavent as long as the correct amount of fuel and air are present,squezzed,ignited and exausted. all the other stuff on the block just aid in doing it.<br />carbs of the late 1800's and early 1900's dripped fuel on a heater in the intake track and the vapors were injested. fuel induction has come a long way since.<br />but the case of the 150 is a faulty pump,faulty pump control,ie pulse limiter or hoses, or a fuel restriction. a logical sequence of testing will isolate it rapidly. my advice would be to test with a remote tank mixed at 50/1 and go directly to the pump intake with it. that will eliminate any hull issues. be aware that you can run a two stroke lean on the air to fuel ratio and scuff a piston.<br />if you have a yamaha dealer nearby go ask for pages 2-35 through 2-46of the 2004 marine technical guide and if you follow all applicable steps it will test about any internal combustion articulated rod engine.
