1999 60 HP Mercury Outboard alarm sounds when you come off plain

[Surfin Moose]

I have a 1999 60 HP Mercury outboard. 2 stroke. 3 carbs. When I start engine idles fine. Runs great. Take out for a spin and come off plain, about a minute or 2 running at 900 rpm alarm sounds everytime. What could problem be? Last year rebuilt carbs. Changed fuel filter. Changed impeller. 2 years ago thermostat changed.

 

[CharlieB]

Re: 1999 60 HP Mercury Outboard alarm sounds when you come off plain

You need to look into the water pump again. If the stainless parts have a 'ring' worn into them from the raised seal ring on the sides of the impeller it is time to replace them as they will not seal well enough to pump sufficiently at lower engine speeds.

 

[Jlawsen]

Re: 1999 60 HP Mercury Outboard alarm sounds when you come off plain

I have a 1999 60 HP Mercury outboard. 2 stroke. 3 carbs. When I start engine idles fine. Runs great. Take out for a spin and come off plain, about a minute or 2 running at 900 rpm alarm sounds everytime. What could problem be? Last year rebuilt carbs. Changed fuel filter. Changed impeller. 2 years ago thermostat changed.

There are specific sequences of beeps, steady, etc., that will tell us what alarm you are actually getting. If you can describe the alarm code we can then tell you what area the problem is in.

 

[Surfin Moose]

Re: 1999 60 HP Mercury Outboard alarm sounds when you come off plain

You need to look into the water pump again. If the stainless parts have a 'ring' worn into them from the raised seal ring on the sides of the impeller it is time to replace them as they will not seal well enough to pump sufficiently at lower engine speeds.

Stream is pumping strong and steady at all speeds and rpm's

 

[Surfin Moose]

Re: 1999 60 HP Mercury Outboard alarm sounds when you come off plain

There are specific sequences of beeps, steady, etc., that will tell us what alarm you are actually getting. If you can describe the alarm code we can then tell you what area the problem is in.

The alarm is a steady Beep, once on stays on, unitl I shut motor off or take up on plain.

 

[carholme]

Re: 1999 60 HP Mercury Outboard alarm sounds when you come off plain

Here is the service manual for your engine:

http://1manual.com/Mercury manuals/Service Manual PDFs/TwoStroke/852572r1/cover.pdf

You must have Adobe Acrobat reader installed to use this manual. If you scroll down to the lower part of the opening page, you will see the various engine components in red. Click on the one you want and when the first page opens, click on the "Save As" icon at the top LH corner of the page and you can save it to your computer.

See Section 3C, Oil Injection, Page 3C-9 for the following:

Problem: Warning Horn Stays On When Ignition Key is Turned to “ON” Position (Engine Cold).
Possible Cause Corrective Action
Faulty Engine overheat sensor. If warning horn sounds a continuous “beep”, the engine
overheat sensor may be faulty. Disconnect tan/blue overheat
sensor lead at bullet connection. Turn ignition key to
“ON” position. If horn stops sounding, the engine overheat
sensor is faulty.

Possible Cause Corrective Action
Problem: Warning Horn Sounds (Continuous Beep) When Engine is Running and Oil Tank is Full.
Disconnect both low oil sensor leads (blue) at bullet connections.
Connect an ohmmeter between sensor leads.
There should be no continuity through sensor. If continuity
exists, sensor is faulty.
Defective low oil sensor (located in bottom of oil tank).

Parts Listing:

http://www.crowleymarine.com/mercury-outboard/3371.cfm

Gerry

 

[Surfin Moose]

Re: 1999 60 HP Mercury Outboard alarm sounds when you come off plain

Thanks Gerry! I will try and let you know what happens.

 

[Surfin Moose]

Re: 1999 60 HP Mercury Outboard alarm sounds when you come off plain

Hey Charlie, I think you might be right. Before I change the impeller or cover or both, could it be anything else? I changed both the low oil sensor (which was defective) and the Engine overheat sensor which carhomle suggested. I also changed the thermostat, which was pretty aweful. I took the boat for a spin. Stream is steady and great above 1000rpm's, weak when idle. When I came back off plain, as always, about 2-3 min later, the steady beep comes on. If I rev it up again alarm goes off. Help , before I loose my freekin mind, lol. Thanks in advance.....
Surfin Moose

 

[ufm82]

Re: 1999 60 HP Mercury Outboard alarm sounds when you come off plain

Moose,
I had an ongoing and frustrating issue with my 150 overheating. It ran great unless you ran it at anything between 1500-2500 and then it would overheat. After replacing everything (and I mean everything) I went back to the water pump and found a groove in the lower housing. I had replaced the impellor along with the upper and the SS sleeve but had not inspect the lower housing. I popped it out and saw a very slight issue were it seals against the lower plate. Replaced that and POOF, it did not do it for the rest of the season last year. Check for the grooves as mentioned. And if you don't have a water pressure gauge, spend $50 and get one. It's one of the most telling gauges you can have on a boat and one of the most frequently gauges not installed on a boat. (Don't understand that either.) It helped me find my problem.

 

[CharlieB]

Re: 1999 60 HP Mercury Outboard alarm sounds when you come off plain

......................... Stream is steady and great above 1000rpm's, weak when idle. ..................

Guaranteed, you will find the problem in the water pump, you just have to look close enough.

Stream should be strong ALWAYS.

The impeller is NOT sealing well enough to the SS parts and not pumping enough water until speed is increased.

 

[Surfin Moose]

Re: 1999 60 HP Mercury Outboard alarm sounds when you come off plain

Thanks Everyone for your help!!! I changed the whole water pump and the seals under the lower plate. I also had some pitting on the aluminum so I got some marine tex and leveled out the surface. Problem solved. She pissin' like a racehorse!!!!! and at all speeds. No more alarm. Stream is cool.

Moose

 

[chris28]

Re: 1999 60 HP Mercury Outboard alarm sounds when you come off plain

I have a similar issue with alarm. I have disconnected the temp sensor, the engine is stone cold, I turn the ignition to 'on' but haven't fired it up and the alarm still sounds continuously. Any ideas?

Here is the service manual for your engine:

http://1manual.com/Mercury manuals/Service Manual PDFs/TwoStroke/852572r1/cover.pdf

You must have Adobe Acrobat reader installed to use this manual. If you scroll down to the lower part of the opening page, you will see the various engine components in red. Click on the one you want and when the first page opens, click on the "Save As" icon at the top LH corner of the page and you can save it to your computer.

See Section 3C, Oil Injection, Page 3C-9 for the following:

Problem: Warning Horn Stays On When Ignition Key is Turned to ?ON? Position (Engine Cold).
Possible Cause Corrective Action
Faulty Engine overheat sensor. If warning horn sounds a continuous ?beep?, the engine
overheat sensor may be faulty. Disconnect tan/blue overheat
sensor lead at bullet connection. Turn ignition key to
?ON? position. If horn stops sounding, the engine overheat
sensor is faulty.

Possible Cause Corrective Action
Problem: Warning Horn Sounds (Continuous Beep) When Engine is Running and Oil Tank is Full.
Disconnect both low oil sensor leads (blue) at bullet connections.
Connect an ohmmeter between sensor leads.
There should be no continuity through sensor. If continuity
exists, sensor is faulty.
Defective low oil sensor (located in bottom of oil tank).

Parts Listing:

55/60 JET 40/45 (3 CYLINDER) 2-STROKE - Mercury, Mercruiser, Force, etc. Parts Lookup

Gerry