9.9 yammi

[basslkjohn]

I've been working on my 9.9 Yamaha all summer. Two carb jobs, new fuel pump, new fuel line. It's a 1994 kicker. After all this work, it still kills after about 15 minutes of running time. Starts on the first or second pull, idles down just right for my boat, and then, after about 15 minutes, just stops. And I can't get it restarted for a couple of hours. I'm out of ideas. First thought it was bad gas and cleaned the carb. Then I thought it might be vapor lock due to high summer temps and the fact that Yamaha has redesigned the fuel pump to channel cooling water through the fuel pump...put in the new fuel pump. Then I thought that maybe the fuel line was the problem, so I bought a new gas hose. So, today on Winnie I got about 15 minutes of good trolling before it quit.

I can't tell you how frustrating it is to be chasing down potential problems that initially seem to be the answer...and then to have the fricken thing quit again. I've at least stopped buying fuel additives and will now spend that money on liquor...until someone can come up with a new idea to solve this ongoing problem. As always, thanks guys for your consideration.

[Crusty old Swede]

Not much help, but I see your motor as having an ignition / electrical problem. It works fine until the bad part gets warm, then stops working until it cools off.

[Valv]

I would suggest electrical too. Is your motor a 2 stroke or 4 stroke ?

A powerpack can get hot then suddenly quit until cooled off, and start the cycle over again.

Have you checked your water pump ? When is the last time you replaced the impeller ? It could be the motor is overheating too.

[marine_man]

It sure sounds like an electrical problem... I'd check to see if you have spark the next time it kills after 15 minutes of run time.

marine_man