2005 F115 power loss problem

[swflpeep]

I feel like I'm taking crazy pills. My 2005 F115(four stroke) loses power while on plane.

PROBLEM: While at normal operating temp, the engine just shuts down and comes back down to idle, never shutting off, but has no power. It skips for a few seconds and then corrects itself when I put it in neutral and then in gear again.(It will actually correct itself while in the process of coming off plane if I return it to neutral then slamming it back full throttle again) There is also an alarm associated with it but nothing shows on the gauges, so I have no idea what the alarm is telling me.

HERE IS WHAT HAS BEEN DONE:

DEALERSHIP #1: Sea trial, and of course couldn't duplicate the problem. Put the diagnostic computer on it and nothing(so they say) They apparantly found a loose wire under the console and said the problem was fixed...it wasn't

DEALERSHIP #1 2ND VISIT. Diagnostic with no results and a sea trial that couldn't duplicate the effect. Replaced fuel water seperator, fuel filters, checked the plugs, made sure the fuel bulb wasn't collapsing. None of this helped.

DEALERSHIP # 2: Sea trial that actually duplicated the effect. Per Yamaha tech advisor, replaced the fuel injectors that they claimed were corroded and the impeller. That still didn't fix the problem.

As a result of these people giving me the warm fuzzy, I keep running the boat and now I get blue smoke on start-up. It does go away but it is a new phenomonon that I am very concerned about.

I now have an appointment with DEALERSHIP # 3 and pray the damn thing doesn't blow up while testing it.

ANY SUGGESTIONS I CAN TELL THESE PEOPLE?

BAD GAS?
IGNITION SWITCH?
WATER IN FUEL?
DEMONS FROM HELL?

Many thanks

Lee

[Ken]

Lee,
I know this is a long shot, but what you are describing could be a faulty thermo switch.
The thermo switch is designed to close at around 180 degrees f. to indicate an overheat condition.
Two things happen, the alarm immediately sounds, and then a few seconds later, the motor will go into what is called "rpm reduction mode", whereby the rpm is drastically reduced by the ignition control and the motor will shake violently.
This is what happens on my 2-stroke 115 - I am assuming the same for your 4-stroke.
I have personally experienced a thermo switch going bad and closing at 130 degrees and giving a false overheat signal.
I would pull the thermo switch (I believe your motor only has one) and testing it in a pan of heated water, and using a thermometer and ohm meter. Cycle the temp several times - up to 180 and back down to 120. You are looking for an intermittent sticky switch.
Or you could try just disconnecting the thermo switch, temporarily, to see if that cures the problem. Only do this if you are confident the motor is indeed NOT overheating.
Good luck [img]smile.gif[/img] ,
Ken K