1999 150 Opti Blowing Fuses???

[twin200merc]

Hi Remember me? I had the 1999 150 Opti With a bad fuel pump that wouldn't start in june... Well It's been running perfect, for about 50-60 hrs. Now It just started (by the dock one day) blowing a 20A fuse. The one that is third down from the top located near the ECM. It ONLY blows this fuse if the motor idles for a little bit like a minute or two. if you just start it and keep it above 1500 RPM it'll run all day, but if you idle two long, even just to pick up a skier, the fuse blows, and the motor stops, and it won't trim or anything...

Any tips or tricks, or a place to start, let me know please :)

Thank You,
Mike

[twin200merc]

I just need a place to start, somthing to do to feel like I'm starting to head in the right direction with this problem... Please let me know, Thank You,
Mike