1998 50 hp idle issues

[islandboat]

Had idle issues with the old vro pump causinf too much oil in the fuel and smoking, fouling the plugs. Removed the vro system, installed new older model 48 spl standard fuel pump. Rebuilt both carbs (floats, needle and seats, ect)even though they were very clean inside. installed new plugs, coil and wires. Bought the OMC manual and did the carb and timing adjustments, they were very close to begin with. New fuel, new fuel lines, fuel filter. Idle timing is at 1* and full advance is 19*.
The engine will crank and warm up if I use the enrichment on the switch periodically. The tach shows idling at 3500 rpm. Not even close to that speed, more like 800. The engine will die almost like the key is shut off after about 5 seconds of idle speed. bumping the throtle just before it dies usually does not help. It's almost like the ignition cuts off. It's not the key switch as it still has voltage back to the engine ignition system. I can use the remote starter switch to spin the engine and it will restart with out having to touch the ignition switch.
What could cause the engine to die even during fast idle (about 1000 to 1200 rpm)? Carbs are not flooding. Why would the tach be so far off? Bad power pack?

 

[islandboat]

Re: 1998 50 hp idle issues

Went back to the boat after a few hours. The tach is back to 1000 rpm for the idle. Actual engine speed did not change. The engine idles after a few minutes warm up. The top carb is ice cold, the bottom carb is as warm as all other parts around it. Engine will idle for a few minutes and then die. Don't even need to touch it. Running it out a bucket of good 50:1 fuel direct to the fuel pump to rule out any other issues.
How much play in the throtle shafts is normal? Any way to reduce the amount of clearance between the throtle shaft and carb's throtle bore? How much slack is OK before the carbs must be replaced? This engine does not have many hours on it.