F115 warning horn souded at WOT

[Seabags6016]

My 2015 F115LB warning buzzer went off after throttling up after leaving a no wake zone. About 3-5 seconds after hitting WOT, it sounded. Brought throttle back, buzzer continued. Shut down engine and rased motor figureing water intake was clogged. It was clean with no obstructions. Restarted motor, water was cooling and flowing out. Horn was silent. Pushed up throttle again, samething. Shut off engine and restarted, ran it at half throttle back to the harbor 15 minutes away. First time out I topped off gas, ran at WOT for about 15 minutes to shake any bugs out for the season. This time, been out for 2.5 hours. All throttle settings.Ran fine with no issues before this. Any ideas? Someone mentiond a battery?

[99yam40]

if you think a battery might be a problem, take some voltage readings.

the more fuel you burn at higher RPMs makes more heat, so check stat, water pump, and other cooling parts

[brian3006]

Do you have any Yamaha gauges hooked up?? they will illuminate a light to tell you what type of alarm it is... Temp or Oil.... given the conditions though..I would look towards temperature alarm.

is this a Salt water engine?

First pull and check or replace the thermostat. The F115 have a 10-degree cooler thermostat than most others. believe it is a 50*C thermostat. . Also on the starboard side of the engine, pull the pressure relief valve.(poppet valve) out and make sure it is clean and does not have trash holding it open. That will cause water pressure loss and not allow it to flow through the block efficiently. and finally, might be time for a new waterpump/impeller. Just because there is water flowing from the tell-tail, does not mean there is sufficient flow to circulate through the block.

Battery is easy enough to check with voltmeter...Check at battery terminals and at engine connections just to verify no corrosion or lose contacts in cables. ...but If it was that low, I do not think the motor would be starting/restarting that easily

[DennisG01]

Water coming out the telltale doesn't necessarily indicate good (or bad) water flow through the engine. It only tells you that at least some water is making it through.

As noted... what did the gauge show?

With the limited info, you're going to have to do some more checking on things - especially if you don't have a gauge. If you can get the engine scanned, that would help tremendously.

Otherwise...

-- Pull and inspect t-stats and passageways
-- Pull and inspect impeller and housing

Unlikely to be the battery based on how/when the alarm was sounding, but that's easy enough to check.

-- Do you not have a voltmeter on the dash? If not, get yourself a cheap digital voltmeter and take readings at the battery with the engine off and then with it running.

[Keithbaja]

That motor takes the "blinky light" not a scan tool per say

[DennisG01]

That motor takes the "blinky light" not a scan tool per say

A 2015 F-series still uses the Winky Blinky? I thought that motors ECM would have been more advanced.

Either way - it can still help you Seabags - but the Winky only monitors in real time - well, more accurately, the ECM doesn't save codes to be looked at later.

[Keithbaja]

Oops,, my bad.. I was seaing the 2000 Yamaha OX66 250 slightly above my post... Great motors,, BTW

[FabricGATOR]

Sea water or fresh?