1997 vmax pro 150

[biggfella68]

I have a 1997 Yamaha 150hp VMAX PRO that starts easily and runs great until it get up to temp then it runs rough then shuts down. It will start right back up and run for a few and then the same die down. I had the carbs rebuilt and the end of last summer and had no problems, ran great but now the problems. i run non ethanol fuel in it and it has not set up long since we had a mild winter. Any suggestions on where to start a diagnosis, my marina said its probably a coil pac but need a second op

 

[ClassicAQ]

Runs rough? As in it's sputtering, missing, bogging down, losing power, etc. How does it sound when it's at temp and idling? When an outboard isn't performing as it should, 90% of the time it's fuel system related. So that's always the best place to start.

Usually if a coil is in question, the engine will run noticeably different all the time. But it couldn't hurt to check it's volts. Below is the service manual for your engine. Chapter 8 describes the instructions for testing coils.

https://www.vansoutboardparts.com/s...uals/535-1997-yamaha-150v-175v-200v-225v/file