coil voltage?

[jaybrown]

So I got spark to my 1978 merc 70hp and im getting 8v to the coil is that enough or should it be 12v?

 

[racerone]

But I do not believe that 12 volts from the battery is used to produce the spark on your motor !--------Serial # of your motor should be posted.

 

[jaybrown]

here is my serial# 4981635 from the square box to the coil im getting 8v and I have spark but it just wouldn't fire????????

 

[racerone]

How many coils on this motor , is it 3 of them ?-----Then the battery is not used for getting spark at the plugs.---This is done by the flywheel magneto when flywheel spins fast enuff.

 

[jaybrown]

yes 3 coils, no voltage there unless the flywheel is spinng. there is spark it just wont fire????????

 

[racerone]

What happens when you spray some fuel into one of the 2 carburetors ?-------Choke working ?------Does spark jump a gap of 3/8" or more ?

 

[jaybrown]

I sprayed gas in both carbs nothing, sprayed in all three cylinders still wont start not even a burp, lots of spark compresion is 120 in all 3 this is a mystery for me. The only thing I haven't tried is hooking up the gas tank line to the motor as the line from the motor inlet to the pump is shot and im going to pick one up this week but dont you think it should of at least fired with gas in the cylinders? yes choke is working

 

[racerone]

Does spark jump a gap of 3/8" , yes or no?----Does spark occur at the correct time , as in have you checked magnets on flywheel hub ??

 

[jaybrown]

yes i put new fly wheel on I just bought 3 new plugs any thing elese you can think of? yes 3/8 spark

 

[sam am I]

Fire Triangle = ig. source (Spark plug spark) + O2 (Reeds/Intake) + fuel (Gasoline).............You are missing one of these (or a combo) still in those cylinders else it would at least spit ("burp") for a few sec's.

Add gas (splash or two) directly into the plug holes, spin plugs in, connect plug wires and crank it...........What happens? Run for a sec? At least got some smoke out of exhaust?

 

[jaybrown]

Nothing not even a burp the only thing I havent tried is hooking up the gas tank to the motor but you would think i would hear a burp when there was gas in the cylinders? Yes I put gas right in the cylinders

 

[jaybrown]

If i wanted to check the timing with a timing light what am i looking for?