1985 Johnson gt150 high rpm problem

[Seacraft79]

my 150 runs fin at 2000-4000 but when i go full throttle it feels like it looses a cylinder or two if i throttle back it comes back i checked spark has week spark on all but one cylinder power packs and rectifier are new please help
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[tashasdaddy]

Re: 1985 Johnson gt150 high rpm problem

check all electrical connections, clean them, don't just look at them. check compression, when were the carbs last cleaned and rebuilt? have you change your fuel line to alcohol resistant lines? if not do so.

 

[emdsapmgr]

Re: 1985 Johnson gt150 high rpm problem

Put an inductive timing light on each plug wire when it starts to miss. It will show you which wires are misfiring or not firing. If you find you have good spark but it still does not run-check the fuel system. Inability to run full speed is also a sign of a fuel restriction, lack of fuel, even a weak fuel pump.