merc 3.0 stalls

jt3kids · 07-01-2012, 04:13 PM

Hey all. First time at the Lake, wonderful weather. Have an older boat, 3.0 merc 4 cyl, mechanical fuel pump, coil, etc. Everything new ( except fuel pump). This thing starts, and runs fine for 10 mins, then stall, like someone shut off the key. the longer I let it cool, the longer it will run. After it stalled I checked spark from the coil, and it was perfect. I bypassed fuel/water filter, and still no difference. new gas + additive for moisture. I took off fuel line intake to Carb and cranked engine. Fuel came pouring out. I disconnected RPM wire from coil ( TACH didn't work anyway), just incase it was that... When its cold, it starts right up and runs perfect. New T-stat, water pump, lower unit rebuild, starter, batt, wiring, IGN switch, etc. When it stalls, you can hear the RPM's start to go down, and then it just cuts out. I am at my wits end. ruining vacation at this point. Any ideas would be extremely helpful. Also, does anyone know of a mechanic that would do house calls tomorrow ( monday) on Gov's Island? Thanks for any help.

07-01-2012, 04:13 PM	#1
jt3kids Member Join Date: Jun 2012 Posts: 24 Thanks: 6 Thanked 1 Time in 1 Post	merc 3.0 stalls Hey all. First time at the Lake, wonderful weather. Have an older boat, 3.0 merc 4 cyl, mechanical fuel pump, coil, etc. Everything new ( except fuel pump). This thing starts, and runs fine for 10 mins, then stall, like someone shut off the key. the longer I let it cool, the longer it will run. After it stalled I checked spark from the coil, and it was perfect. I bypassed fuel/water filter, and still no difference. new gas + additive for moisture. I took off fuel line intake to Carb and cranked engine. Fuel came pouring out. I disconnected RPM wire from coil ( TACH didn't work anyway), just incase it was that... When its cold, it starts right up and runs perfect. New T-stat, water pump, lower unit rebuild, starter, batt, wiring, IGN switch, etc. When it stalls, you can hear the RPM's start to go down, and then it just cuts out. I am at my wits end. ruining vacation at this point. Any ideas would be extremely helpful. Also, does anyone know of a mechanic that would do house calls tomorrow ( monday) on Gov's Island? Thanks for any help.