1989 Mercruiser 3.0 - Stalls at start

[spelk1]

1989 Mercruiser 3.0.
It stalls about 10-15 seconds after startup. I’ve replace all the fuel filters, and am getting gas to the carb. Plug wires and distributor looks good. I’m getting 12v on the coil with the key on.
Any thoughts on what to check next?

 

[alldodge]

Need a motor serial number or at least tell us if you have DDIS, points or electronics. The 89 3.0 shows only DDIS

 

[spelk1]

My motor serial number is 0C460015 and it is a points ignition.

 

[alldodge]

According to Merc that motor came out with DDIS, probably changed.
Also your saying it gets 12V with key ON, and it should not

If the points an condenser have not been changed I would do so. What I think is happening, when the motor is cranking everything is getting 12V. Once it starts the ignition is getting 9V or so. If the Condenser is not up to spec it doesn't last long because it continues to leak power to ground. This causes spark to continue to reduce.

There may be another issue but this is why I'm asking if they have been replaced ?

Then check for a resistance wire or ballast resistor