No spark

I have a boat with a 1984 omc 3.8 that I am restoring.Boat ran fine I changed gauges and now no spark.Prior to this I have changed all connectors,ignition parts, solenoids ect.I have 4.8 volts to positive side of coil with key on.My buddy held high tension lead while I cranked it he said he got a little jolt then tapperd off.

Re: no spark

Re: no spark

K.C.B. said:

I have 4.8 volts to positive side of coil with key on.

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where do you have the other lead of your meter when you are reading this 4.8?

Re: no spark

Re: no spark

ground

Re: no spark

Re: no spark

you mention gauges - make sure the tach wire is on the coil (-) side. or just disconnect for testing

As far as positive side goes, there should be close to 10V there with key on. there is a resistance wire in the feed..approx 2 ohms as memory serves. Should see almost full 12V during cranking as the resistance wire is bypassed by the start circuit.

might want to disconnect the ESA module too for testing, although, like the tach, it should only affect the negative side of the coil, not + side, but best to disconnect everything for testing, just make sure the coil supply wire (resistance wire) has proper voltage. note, the resistance wire should get quite warm when key has been on for a while.

if V is not right, check for full 12V at the other end of that resistance wire, then work back towards key switch

Re: no spark

Re: no spark

Thanks will advise.

Re: no spark

Re: no spark

checked for voltage on positive side of tach still seemed a bit low.I took off grey wires off neg side of coil and it startes right up.Now how do I tell if switch is bad or esa? Thanks