Expert: Everett Peacock - 3/23/2010

Question
I am helping a friend with a mercury force 40hp 1992 he believes, the rectifier went out on the boat last season, he just picked up the part and I reinstalled the new one, we have spark again but it is really weak,even directly off of the coil, both coils and new one he bought when he thought that was the problem last season.  Any idea why we have such a weak spark?

Answer
If the tach does not work and the engine will not charge then the rectifier could be bad..the items in the system must be checked indivualy, sensor coils or trigger should have at least 3 volts at cranking speed...charge coil should have 120 or higher...coils checked for shorts, the kill switch, magnets, and flywheel...all volts are ac voltage taken with a peak voltage meter...if all items are good replace the powerpack..
sounds like a bad stator...
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