1976 233 Mercruiser Starts at turnover then loses spark on run, Help whats up?

[JB boat poor]

Just fixed the no spark problem with a new starter solinoid run great for 2 hours, now revs at starter key position then when I release the key back to run and she stalls. The good engine has power at the plus side of coil on dwell an is bottomed out then goes to 36 or so on dwell at start. The bad engin has no power on the dwell meeter at run key position the bottoms out at start key position. ANY HELP PLEASE????

[Don S]

Could be a failed igntion switch or even a safety kill switch or resistor wire or corroded terminal or blown fuese or .............. Get the pictuer.
you should have power to the coil with the key in the run position, if not, you have to trace the wire to the switch and back to the engine to find out where you lost the power.

[JB boat poor]

Could be a failed igntion switch or even a safety kill switch or resistor wire or corroded terminal or blown fuese or .............. Get the pictuer.
you should have power to the coil with the key in the run position, if not, you have to trace the wire to the switch and back to the engine to find out where you lost the power.

Just put in a new ignition switch and resistor wire when I did the starter solinoid. I did see that they have disconected the resistor wire that runs from the chock to the + side of the coil, but thats done on the engin that works too.

[haulnazz15]

You need to check the voltage at the coil when the ignition in the "run" position. You should have at least 6V if you are running power throught the resistor wire. Otherwise, the coil is not getting power to run the engine after you release the key from the "start" position which is giving the coil a full 12V. I believe the wire on the "s" pole of your starter solonoid should be providing the running voltage to the coil.

[04fxdwgi]

#1 on the resistor wire / ballast resistor. The start position bypasses the resistor wire to supply the extra oomph of the 12 VDC to the coil to get her to start (since battery voltage normally drops when starting), then goes back to the reduced voltage for running (provided the wiring is correct). If the resistor is NG, then you'll have no power to the + side of coil when in run position. If you keep full 12 VDC on reduced voltage coils, they will overheat and come unglued.

[JB boat poor]

Thanks for your help don. It's running great now, it was a bad connection going to the accesories as soon as I replaced the end we had power to the coil in the on position.
JIM