BoatBanter.com - View Single Post - Mercruiser 7.4 runs great at times and horrible 5 minutes later

Jim

wrote:
Hi,
I have a 7.4 Mercruiser that is giving me fits. The boat sat for some
time and may have had bad gas. It will start and run great for 5
minutes and then will stumble and even backfire sometimes. I have
read that if water gets in the carbeurator it will not pass. Is this
a possible problem. Other possibilities are check valve (seems to be
OK) and fuel pump. I have changed the fuel separator and fuel filter
and still am having the problem. Any ideas??

Rick

Crossfire, moisture in the distributer. Bug nest in the fuel vent.
Defective coil. Stuck choke. Overheating. Stuck thermostat.
Get a manual and read it. You will learn enough to do some basic
troubleshooting.