Mercruiser 888 Won't Stay Started

[ctanke]

Hey guys,
I have a 72 Mercruiser 888 that we can't keep started. Ran great this past spring, but now it will only start up for a second and then quit. Since the last time it ran we did redo the exhaust manifolds, a new water pump, starter, replaced the gas pump gasket (kept original pump,) new gas fule seperator. We also took off some of the gauges to repaint the bezels. All out the Tac and Spedo have been hooked back up.
We know we have fresh gas squirting into the carb, and of course we have spark. She really wants to run, but just conks out every time. We think it's electrical, but can't figure it out. Sure would appreciate where to start looking. Thanks in advance, Chris

 

[Bt Doctur]

a bit more info, do you mean it runs and then stops or does it stop when you release the key from "start" position

 

[ctanke]

I think that's correct, it fires right up strong but when I release the key then it dies, time after time.

 

[Bt Doctur]

you missing the 12v to the coil , it comes from the ign switch. Check to see if there is 12v at the + side of the coil with the key "on"
If not ,start tracing the purple wire.Being a 1972 it may also have an actual ballast resistor.