Alarm going off when throttling up on Mercury

**blowitup** · 05-25-2016, 09:43 AM

Purchased boat with Mercury 225 pro max 1995,Just put on hose and idles fine but when throttling up beeping starts.Any ideas where to start diagnosing?

**skeeter91** · 05-25-2016, 11:58 AM

is the oil injection still intact?if so,id pull the pump and drive shaft and have a look at the drive gear on the crankshaft.they are notorious for stripping teeth.

**Go Time** · 05-25-2016, 01:11 PM

Describe the alarm... comtinous or pulsing beep

**FUJIMO** · 05-25-2016, 02:21 PM

Mid 90's first generation 3 litre gearcases also had a side water intake issue, in that the shape of the gearcase had a hump on the sides, just ahead of the water intakes themselves, causing air to be introduced to the intakes. This happened to be where the pinion gear was inside & they thought they needed the humps there. Mercury redesigned/improved the gearcase shape & intake design the following years, and the problem mostly went away. This may or may not, be part of your situation.

**blowitup** · 05-25-2016, 03:02 PM

Go time,its a pulsing beep/beep.This is the history:I was under the dash cleaning up wiring and found tan/blue wire broken or cut going to alarm buzzer and the purple was connected.So i reconnected tan/blue.I finally got around to getting the boat ready for season and now beeping sound off idle is present.The boat has twins so i can try robbing parts from other engine.

**blowitup** · 05-25-2016, 03:10 PM

Skeeter yes oil injection still present,Do not want to remove because boat has twins and separate tanks.

**XstreamVking** · 05-25-2016, 03:32 PM

Dunno if yours has it, but there is a neutral safety switch on the 3.0's that will make the comp think the motor is in neutral and will beep and limit the r's to 1500-1800 when you give it throttle. It's on the shift slide. Disconnect and jump the 2 motor side wires together to test. Just a guess....

**blowitup** · 05-25-2016, 03:37 PM

X have no switches,I can Rev to 6k

**XstreamVking** · 05-25-2016, 04:04 PM

Darn, oh well. Back to the oil system

**blowitup** · 05-25-2016, 04:09 PM

Going to take oil shaft out tomorrow.I'm burned out chasing the "beep"

**transomstand** · 05-25-2016, 04:43 PM

Originally Posted by blowitup

found tan/blue wire broken .So i reconnected tan/blue.

That's the temp sender wire, you might be running hot.

Everybody please note, it's a 95 225 Promax, so it's a 2.5

**FUJIMO** · 05-25-2016, 06:54 PM

Originally Posted by FUJIMO

Mid 90's first generation 3 litre gearcases also had a side water intake issue, in that the shape of the gearcase had a hump on the sides, just ahead of the water intakes themselves, causing air to be introduced to the intakes. This happened to be where the pinion gear was inside & they thought they needed the humps there. Mercury redesigned/improved the gearcase shape & intake design the following years, and the problem mostly went away. This may or may not, be part of your situation.

...In a twin engine installation, this gearcase design shape problem was amplified, due to the crabbing nature of the gearcase as it goes through the water, because twins have a tie-bar that is always adjusted to "Toe In". (Which is incorrect by the way, but everyone does it.)

**blowitup** · 05-25-2016, 08:38 PM

Swapped warning modules with no success.Leaning towards stripped oil injection gear it has hall effect magnet pickup on top of gear housing.
Transom,can post wiring diagram?It beeps even stone cold with water on while raising rpms .

**Dave Strong** · 05-25-2016, 09:44 PM

Temp will be a steady beep. Beep Beep = oil injection.

Dave

**eli** · 05-25-2016, 11:29 PM

i had a steady beep i traced it to the new livorsi temp gage un hook power to gage tone was slient what i had to do was run a jumper from neg to neg on batterys all quiet must be a ground thing on one of the batterys .