Re: HELP. Old OMC 3L 4cylinder will not fire
you could pull the number one plug and or use a spare plug and hook the number one plug wire to it ... ground the outer case of the plug wire to engine block and check for spark when turning it over
make sure its a good white spark that jumps 1/4 inch - if its a red/orange weak spark check points gap and swap condensor
if the points gap is far too big it won't have time to charge the coil for a good spark
if the gap is correct then the condensor isn't assisting in e/m charge collapse.
the reason i add this is a spark plug will spark with hardly any volts in atmosphere conditions (ie when earthed to block in open air) but that doesn't mean its sparking when in the cylinder under compression
and try running a jumper directly from the battery +ve to the coil +ve
if it sparks now then you have a problem with the positive supply to the +ve coil terminal - check ignition wiring - lanyard switch & ignition switch
also try disconnecting all wires from the -ve side of the coil except the one from the points - could be tacho shorting
good luck
adam
