80/81 Black Max 200 carbed motor not starting

[maineidyl]

New to me Mercury 200. Motor sat for a few years. Drained float bowls and pumped clean gas through the carbs. Motor turns over perfect. Will not start. Checked plugs and one on each bank is not firing. Checked to see if it was the plugs but it is not. Going to clean terminals on two nonfiring and see what happens. Would two non-firing plugs keep the motor from starting? I thought it would start but run rough. Am I correct to assume the stator is ok ir 4 out of 6 plugs are firing?

Tom

[scc82]

What cyl don't fire. If on same side it's most likely a power pack. If on different sides could be both packs or a trigger. Stator is most likely good jmo.
Stan carson.

[maineidyl]

Middle on left side, top on right side. I took a bettr look and see some corrosion on ground for these two. Going to clean and try again. Still not sure that two non-firing plugs would stop engine from starting.

[scc82]

No it would still fire.
Stan carson

[j_martin]

Should fire. #1 and #4 share the same coil in the trigger assy. Some faults in a switchbox can take out the opposite cylinder also.

I fought one of these no start problems a few years back. Turned out the starter was weak and not quite turning it fast enough. Had the armature turned and threw in new brushes and it's golden.

What happens is with the orientation of the starter, brushes down, all the debris that comes off the brushes collects around them and partially shorts it out. It's a pernicious process, so it sneaks up on you without being noticed. Excess current draw is the definitive diagnostic. Easily measured with a magnetic ammeter.

hope it helps

[Motv18]

how are your counting

1v4 or 1v2
2v5 or 3v4
3v6 or 5v6

check the magneto wires, plug wires, individual ground, are the cylinders plugs wet. make sure coil 4 isn't pluged to plug 1 and vice versa. stuff like that. way to simple in 80 for much to be wrong unless its broke.

[maineidyl]

It's alive. The motor started right up after I cleaned the two grounds. I turned the key,pushed down and held it for 10 to 15 seconds to choke and then it fired right up. Idles perfect. Now to put a new water pump, thermostat etc. and seatrial it.

[scc82]

Good news. Check the spark while it's running one cylinder at a time verify the timing and let it rip.
Stan carson.