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