Yamaha F115 cutting out

Hey guys i need to pick our brains a second. The last couple time out my Yamaha F115 has been cutting out on me. The first time it was at idle and It just shut off. I got a steady alarm when I went back to start it up. The primer ball wasn't hard so I pumped it and it started. As soon as I got up on plain (WOT) the motor cut out, recovered and cut out and so on. After putting it in neutral and starting over it ran good at a lower RPM as soon as I reached WOT it did it again. The thing is when it cuts out the motor recovers real quick. Once the motor is warmed up the problem goes away until the next time I get out. So I have a hard time believing there air in the line or a fuel pump problem. I have replaced the primer ball and checked all battery connections.
Thanks for your time. All suggestions are greatly appreciated.
Jeff

My 130 V4 did something similiar. It was overheating, and i replaced the thermostats and a water intake valve (for when it's really up to speed), I don't know the name but it wasn't too difficult to replace. Problem solved.

Tested the old thermostats and one was opening up slower and not as much as the other one.

[boats.net]

Probably need to put it on computer diagnostic to test elect system. Check fuel pressure to see if pressure drops when eng. stalls.

Hey guys i need to pick our brains a second. The last couple time out my Yamaha F115 has been cutting out on me. The first time it was at idle and It just shut off. I got a steady alarm when I went back to start it up. The primer ball wasn't hard so I pumped it and it started. As soon as I got up on plain (WOT) the motor cut out, recovered and cut out and so on. After putting it in neutral and starting over it ran good at a lower RPM as soon as I reached WOT it did it again. The thing is when it cuts out the motor recovers real quick. Once the motor is warmed up the problem goes away until the next time I get out. So I have a hard time believing there air in the line or a fuel pump problem. I have replaced the primer ball and checked all battery connections.
Thanks for your time. All suggestions are greatly appreciated.
Jeff

Jeff,

Take my adivce and take it in for service. Mine was doing the exact same thing. Motor started off by cutting out and recovering here and there (like hick ups). Boy it would **** the hell out of me at 45 mph. I replaced the plugs, checked grounds, fuel lines, fuel preasure and tank fuel pick up. It continued to do it and little by little it got more severe were it would turn off complety. I ignored it since it would still run and idle fine when restarting. I learned the hard way ran ten miles away from the dock motor kept turning off everytime after it reached 2000 rpm. Motor would idle fine but could not get boat to plane because it would turn off at 2000 rpm. It took me hours to get back to the dock. What a nightmare. Took it in for service and they replaced the computor and wire harness $800. Good thing motor was still under warrently. I didn't pay a dime. Motor has been running fine 50 hours tested so far with no problems. Hope this helps.

Just a little update on my problem. I have taken the motor into two dealers they have both hooked there computer to the motor and no codes have showen up. One of the dealers actually put it in the water three times and could not get it to act up. Since my last post i have replaced the teather switch, tried a new ignition switch, new cable harnes, checked battery cables and grounds. I have changed spark plugs, oil and filter.
This problem only happens when i first start the motor for the day.I have a Yamaha T-8 kicker motor tied in with a gas shut off that a recently installed. once the big motor won't start i'll start the kicker and motor out and keep trying to start the main motor. After about 15 min. or so of me tinkering around with the main motor it will finally start. If i run it at about 3500 rpms for a while and get it warmed up it will run perfectly the rest of the day. No matter how long i stop and fish (up to 4 hours) in one spot it will always start and run good the rest of the day.
Both dealers think its a electrical problem. How ever if its electrical i would think that it would happen later in the day. I think it has to be some type of sensor. Maybe a o2 sensor or a fuel sensor. Would they show up on a system check when they hook it up on the computer? Anyway this is getting frustrating you guys have any ideas?

Thanks, Jeff