Help please Nissan 5hp NS5B 369-1 outboard

Hi,
The outboard is on a sailboat. Initially there was a problem with the fuel line, or we thought. Had hole in it and sucked air in fuel line. I changed the fuel line. same as before, it starts up easy and runs for maybe 5 minutes and dies. It is definitely getting fuel. I check the filter and the line to carb. I also tried some starter fluid to see if I can start it again, but it didn't. But after the engine cools down it will start again and it runs for a little while. I am convinced it is electrical. It could be a bad coil or alternator, or other electrical part. I am hoping somebody with experience could give some advise as how to troubleshot this issue.

Thank you, Jeff

Waterpump checked and working ?---------------Put a timing light on it and see if it looses spark when it quits.

Racerone is right. There aren't any shortcuts. You need to diagnose the problem, with the aid of your Factory service manual, Part# 003-21035-1, $45.00, available from any dealer, including me. Either you are overheating to the point where it won't run, or you have an electrical component, such as the CD, that is failing when warmed up. I trust that you are running TCW-3 oil in the fuel, at a 50:1 ratio, correct?