Alarms on 525's

[Carguy]

I have an alarm going off after running for an extended period of time. Not beating on the boat but after running 4500 rpms during a poker run ill get an alarm and slight loss of power. When I come off the throttle the alarm goes away. Any help would be great. I have merc 525's and xr's.

[Sydwayz]

Sounds like a temp spike, either water, antifreeze, or oil. Could be a bad sender.

The motor is going into limp mode, restricting you to 75% power.

Only way to find out for sure is to hook it up to a computer scanner.

[glassdave]

yep, sounds like temp spike to me to. Is that closed cooing or raw water? I had a very similar problem with the 525's in the Donzi. Turned out to be a loose hose letting air into the system. Not enough to make it run hot but enough to allow a big temp swing at the sensors. Mine has two different sensors, one for the gauge and one for the warning buzzer. Gauge read fine but shooting temp gun at the sensors showed 160 at one and 190 at the other.

[Carguy]

Its closed cooling. Makes sence. Now I just have to find someone to fix it before cumberland. Never a problem unless running for a while.

[Sydwayz]

If you have fresh water flush fittings, make sure everything is clear and closed and sealed when running. If one is sucking air, it could do weird things like this with temp spikes.

How is your water pressure? Same on both sides?

[Expensive Date]

Because the alarm goes away when you get off the sticks it most likely is oil pressure/ water temp.Is the oil over full? it will expand when hot if the crank throws start hitting it it can airate.This will cause bubbles in the oil when the bubbles go past the sensor they will be read as no oil pressure.

[MahopacMarine]

Its closed cooling. Makes sence. Now I just have to find someone to fix it before cumberland. Never a problem unless running for a while.

You know who to call. Bring the boat down.

[Gladhe8er]

Its closed cooling. Makes sence. Now I just have to find someone to fix it before cumberland. Never a problem unless running for a while.

You still keeping the boat at Nicky's? He should be able to fix that quick.

[Carguy]

You still keeping the boat at Nicky's? He should be able to fix that quick.

I've been keeping it elsewhere. He tried chasing this last year a little, came up with nothing. Really hasnt been a issue for me because I do so few poker runs. Mahopac boys been taking care of her this year and exceeding expectations. Worth the drive. Im just the worlds biggest procrastinator when it comes to boating.

[Gladhe8er]

I've been keeping it elsewhere. He tried chasing this last year a little, came up with nothing. Really hasnt been a issue for me because I do so few poker runs. Mahopac boys been taking care of her this year and exceeding expectations. Worth the drive. Im just the worlds biggest procrastinator when it comes to boating.

Yeah, those Mahopac boys know what's up

[Expensive Date]

Let me know what you find but one of my 6.2s did the same thing once.The fact that the alarm goes away when you lower rpm it is not a constant alarm that would require shutting the engine off.I had just topped of the oil then ran for about 20 miles you might want to check your oil temp and see if the is a relation.