Helm/console wire diagram

[Wroberts20]

Hey guys. New member here. I have a 1983 sea sprite continental mark ii with mercruiser 140 inboard. I am having problems getting this engine to fire. I can only get it to barely cough. I checked spark. It was weak and yellow. I put new plugs cap wires coil points and condenser with same outcome. I got to looking under the console and the wiring is just a mess and spliced everywhere. I'm looking for a wiring diagram to try and sort that rats nest out. Any help would be greatly appreciated

 

[alldodge]

Try this

 

[dwco5051]

Before I would get too deep into the wiring I would suggest a couple of quick tests on the ignition system. First check the voltage on the hot side of the coil while someone cranks over the engine. A weak battery, starter problem, or engine problem may be dropping the voltage enough to cause a weak spark. You can also hot wire the coil and perform the same measurement while cranking. For those of old enough to remember our every day driving pieces having breaker point ignitions the trouble shooting is fairly simple and got us home when the ballast resistor went south. I have a couple of times over the years found defective condensers right out of the box.

Edit: Also check and be certain the ground from the battery to the motor block is al clean and bright along with all the other battery cables.