Audible Alarm - Maxum Boat Owners Club

wgalmond · 05-26-2015, 09:09 PM

Hi guys,

Had an issue last summer, and it's back again this year. Boat started up and idles fine. Took her for first cruise of the season over the weekend. Temp was about 150-160 and been running for about 10-15 mins. As soon as I hit the 5mph wake zone, I have her some throttle and immediately the audible alarm started. Backed down on the throttle and it stopped. There was a decent chop in the water and a good breeze, about 10-16knots.

Tied up for a few hours with a buddy and we disconnected the reservoir bottle for the gear lube. Wired it together and the audible was constant, so we knew the bottle was working correctly (so we think) Left it disconnected to troubleshoot when I was underway again. Audible alarm still occured so we can rule out the reservoir bottle.

Last season I replaced the OP sensor because she wasn't staying running for more than a minute. That fixed the problem.

So I believe I am down to the temperature sensor. When boat starts up, the temp goes up to 175 as it should. Steady climb. OP is good at roughly 50-60 once warmed up.

Any additional thoughts on my next step, because replacing the temp sensor?

Alpha 1 Gen 2. V8 220horse power. 2000 Maxum SCR 2400.

Thanks!
Bill

mmwjr · 05-27-2015, 01:08 AM

Bill how old is the water pump impeller and exhaust manifolds and elbows?

I would use a handheld IR temp sensor and take readings of the t-stat housing and exhaust at the rpm where the alarm comes on.

shrew · 05-27-2015, 03:28 PM

Low Lube is usually short chirps. Constant tone is more serious, such as overheating. What did the temp gauge read at the time the alarm was sounding? Oil Pressure?

wgalmond · 05-27-2015, 05:40 PM

Hi Shrew, thanks for input. It pretty much starts quick chirps, but they stays steady for about 5 seconds. I back off throttle and it stops. Then sometimes if I throttle back up, it starts again.

Temp was steady at 175. I could see it climbing as the boat was "warming up" Same as the OP. Goes up to 40 on startup, then climbs to 55-60 and stays steady.

wgalmond · 05-27-2015, 05:42 PM

Hi Mike,
Water impellar was changed season before last. Not sure about the manifolds and elbows. What are you referring to by elbows?

I can see about getting an IR temp sensor to try what you suggest.

mmwjr · 05-27-2015, 07:04 PM

Quote:

Originally Posted by wgalmond

Hi Mike,
Water impellar was changed season before last. Not sure about the manifolds and elbows. What are you referring to by elbows?

I can see about getting an IR temp sensor to try what you suggest.

Elbows are bolted on top of the manifolds and inject the raw water into the exhaust stream to cool the exhaust, most people call the risers however a riser is a 3 - 4 inch extension that goes between the manifold and elbow on big boats so that the elbow is above the water line.

mmwjr · 05-27-2015, 07:07 PM

Your OP is good and while the temp sounds ok I do not trust helm gaffe until I verify with an IR sensor. Also helm gauge only reflects engine temp and exhaust is down stream.

With that said alarm sensor is next to gauge sendor so they should read them same temp.

wgalmond · 05-27-2015, 08:58 PM

Do you know how much IR Sensor's are? Do you have a recommendation for one?

mmwjr · 05-27-2015, 09:23 PM

Not sure where in the world you are, we have folks around the globe here.

Sears, Harbor Frieght, Automotive store all have them and not much different. The cost is $50 max.

Kevlar7r · 05-27-2015, 09:36 PM

Could be the oil pressure sender as well, however your symptoms sound more like a temp issue.

The gauge sender is separate from the alarm sender. Just another thing to check.

wgalmond · 05-27-2015, 09:37 PM

Thanks I am in RI. I can look around for one.

Kevlar7r · 05-27-2015, 09:38 PM

Quote:

Originally Posted by mmwjr

Elbows are bolted on top of the manifolds and inject the raw water into the exhaust stream to cool the exhaust, most people call the risers however a riser is a 3 - 4 inch extension that goes between the manifold and elbow on big boats so that the elbow is above the water line.

On the mercruiser parts lookups, what you are calling an elbow is called a riser, and what you are calling riser is called a spacer. There doesn't seem to be one correct nomenclature for them.

wgalmond · 05-27-2015, 09:39 PM

Hey Kevlar,
I replaced the OP last summer. As for the gauge sender, I believe they are separate like you mention. I disconnected the temp gauge hardness and the temp went right to nothing (with the boat running but idle anchored) When I plugged it in it goes back to where the temp was (160-175) So that is why I am thinking the temp sender itself?

mmwjr · 05-27-2015, 09:47 PM

Quote:

Originally Posted by Kevlar7r

On the mercruiser parts lookups, what you are calling an elbow is called a riser, and what you are calling riser is called a spacer. There doesn't seem to be one correct nomenclature for them.

Agree

Kevlar7r · 05-27-2015, 09:48 PM

Quote:

Originally Posted by wgalmond

Hey Kevlar,
I replaced the OP last summer.

Sorry, missed that on my skim through the thread.

mmwjr · 05-27-2015, 09:49 PM

Quote:

Originally Posted by wgalmond

Hey Kevlar,
I replaced the OP last summer. As for the gauge sender, I believe they are separate like you mention. I disconnected the temp gauge hardness and the temp went right to nothing (with the boat running but idle anchored) When I plugged it in it goes back to where the temp was (160-175) So that is why I am thinking the temp sender itself?

Temp sendor for the gauge and temp switch for the alarm, both are mounted in the t-stat housing.

Gauge sendor changes resistance to vary voltage on helm gauge to reflect temp.

Alam switch is normally open and closes if the engine gets too hot, this completes circuit to ground to sound alarm.

itsabowtime2 · 05-28-2015, 03:50 PM

I had the same issue with my Alphas a few years ago. New impellers as well. Not sure if I got a bad batch or did something wrong during the install but I switched them out again and the problem was gone.

I got my IR gun at Home Depot. Take several readings, both manifolds, risers, block.

3 reasons you get a warning alarm while running, low oil pressure, running hot, or low gear lube.

Pilotrob25 · 06-01-2015, 08:16 PM

Any luck with the alarm? I got the same issue

mmwjr · 06-01-2015, 09:53 PM

Quote:

Originally Posted by Pilotrob25

Any luck with the alarm? I got the same issue

start a new thread describing what is occurring.

wgalmond · 06-15-2015, 08:38 PM

This Sunday I took the boat out for a ride. Alarm still sounding. After changing the OP switch last summer and eliminating the gear lube reservoir, I disconnected the alarm plug for the audible. Sure enough, on my way back to port, NO ALARM. So my guess is it's a faulty temperature sender. Picked up a new one today ($31.00) and will be changing in next day or so. I will post the results!