trying to help my buddy fix up a 67 80 horse electric shift. we had it running, but then it just starting turning over, with what seems to be no spark. so we are pretty sure it is the ignition coil being fried.
the first time we hooked up the new ignition we for some reason put the coil on the Accesory spot on the ignition and i believe we fried the coil as the wire to it were very hot and starting to melt insulation on them, that was our bone head
so he went and bought a coil, and the parts guy tried to get a cross reference number, and gave us a coil that doesnt look anything like the original. the part number for it matches a 68 and i cant find a 67 part number anywhere.
the new coil has a spot to hook to the distributer, a positive screw (for the white with red stripe wire) and the it has a ground where it mounts to the engine block.
our old coil didnt seem to ground to the engine block at all, and it had spots for negative (two black wires) and positive (white with red stripe) and a wire to the distributor.
do we need a different coil? when we hooked up the new one, the white with red stripe wire has power until we connect it to the coil then it shows no power with our test light. and of course the engine wont start.
All I can tell you is how it is SUPPOSED to be. The red/white wire is a resistance wire. I suspect is is burned or corroded nearly in two somewhere. That would cause your zero voltage when loaded. OR the key switch or other wiring is at fault. You will have to back-trace it till you find the fault.
Red/white goes to the + terminal on the coil. Black one goes to the - terminal (goes to the breaker points). No ground wire---at least not on the correct coil. The other wire on the - terminal is a tachometer signal source.
BTW, the red/white resistance wire is a one ohm resistance.
on a side note the repair book we have shows the opposite of what you said and what is logical. it says white with red stripe to the negative and the two black wires to the positive.
so now we just need to find the correct coil as the one we have has no where to connect the two black wires, and i dont think they can just be grounded correct?
we tried just grounding them since the mounting hole of the coil had a metal band on it, like it was for ground for the whole coil, meaning it would connect to the engine block and ground. and thats what made our white with red stripe "lose power" when connected to the coil.
im hoping we can find a coil that will work off of a car. as it will probably be much cheaper.
so far i know the coil cant have a resistor inside it. now i just need to know what model of car would work, or some other specifications on what it should do voltage wise
Automotive parts while a lot cheaper are NOT for use in a marine application. They are not designed to prevent all of the bad things that can happen to your motor.
such as...? i wont argue, but last time i researched this the only thing people had to support it was that the parts are not sealed like boat parts which could result in explosions, because the unit is not sealing in the sparks it creates, which is dumb. there isnt more gas fumes in a boat engine than a car engine, aside from an inboard which actually has the gas in a sealed compartment, along with the engine.
but i will agree car parts are not the best way to go as they are not specific to the boat, but when it is a 67 boat engine why spend over 100 on one part when the engine is only worth a few hundred. rather than spend 20-30