1965 Seahorse 18hp ignition timing basic question

[stjon]

Hi all - I have just replaced my coils (thanks to all the great info on here!) so I have 2 strong sparks. The timing looked roughly right so i hoped I'd get it running rough at least - the marks on the flywheel looked to be aligned with the mark on the stator when the points were about to open. I thought I would try a trial run in a barrel but all I could manage to get was an occasional loud 'bang' misfire, and I wondered if it's possible I have put the flywheel on 180 degrees out of alignment so cylinder 1 was firing when it should have been cylinder 2? I've read in a guide that the flywheel would have 2 marks on one side to indicate the top cylinder, but I can't see any on mine?

 

[kodibass]

Re: 1965 Seahorse 18hp ignition timing basic question

Your flywheel should only slip on when it's in line with the crankshaft key, I have more than once hooked up my spark plug wires backwards & got a backfire, make sure the crankshaft key is in, & in good shape' torque the flywheel nut to proper torque. check the routing of the plug wires, good compression in cylinders, & a properly working fuel system should = run.

 

[F_R]

Re: 1965 Seahorse 18hp ignition timing basic question

Agreed, more than likely your wires are on the wrong plugs. How to tell for sure?? Position shaft so one set of points is about to open. Now, follow the wire from the coil associated with that set of points, to the spark plugs end. It goes to the cylinder with the piston at or near the top of the stroke. This applies to any motor.

OK, even easier: For your OMC Universal Magneto, the wire from coil nearest the front (forward) of the motor goes to the upper cylinder.

 

[stjon]

Re: 1965 Seahorse 18hp ignition timing basic question

Hi again - plugs/leads both connected in correct order. I suspect timing? I will start from fresh and get it spot on. Also plugs were not wet when I removed them to check so will have to look at the fuel supply as well. Will report back when I am allowed time to look at it!!

 

[Chinewalker]

Re: 1965 Seahorse 18hp ignition timing basic question

Do you have the correct primary lead going to the correct set of points? When looking downward at the mag plate, the green wire (the one from the bottom side of the coil) will travel COUNTER-clockwise to the nearest set of points. The wire needs to be tucked safely under the coil lams to avoid rubbing against the crankshaft.

 

[stjon]

Re: 1965 Seahorse 18hp ignition timing basic question

Chinewalker - I shall check! I was careful to reassemble correctly but the small wires leaving the rear of the new coils looked slightly different to those on the old coils, so its possible I messed up.