Mercury 850 Hot Start Issues

[BoleBerry]

I have been trying to pinpoint an issue I've been having with my 79 Mercury 850.

It will start when cold, and run with no issue. It sounds and runs strong once warm. I can run it for as long as I want to, but if I shut it off for 20 minutes or so, then try to restart, it will not refire. If it only sits for 2-3 minutes, it will fire right up.

Some of the things I have already done to fix unrelated issues are replacing the fuel bulb, changing out the water pump, and new spark plugs. I have cleaned the carbs, but made no adjustments. The problem was present before and after doing the things listed above.

I have compression tested the motor and its showing even numbers across the board.

Any help would be greatly appreciated.

 

[merc850]

Could be the trigger unit, when motor won't start check for spark.

 

[jimmbo]

Welcome to iboats

After it sits for 20 minutes or so, and won't start, have you tried using the Choke again? Even Numbers for Compression, doesn't mean much, as they could all be evenly Low.
Check all Electrical Connections for good Contact

BTW, 1977 was the last year for an 850, in 78 it was rebadged as an 800, then in 79 as an 80. Your engine would a 73, 74, 75, 76, or 77, assuming it is 4 cylinder. If it is a 6 cylinder, then it is from the 1960s

 

[Faztbullet]

If ADI ignition my bet is stator...