Logo
FULL SITE MENU

1987 Mercury 60hp buzzer alarm

S

slk

Member
I have a 60 hp engine 1987 that I just put a new impeller in. Water shoots out very good now. At FULL throttle only the darned buzzer alarm goes off. At normal speeds it never goes off. This engine does have the oil injection system. To be on the safe side I added oil to the gas and ran it and at FULL speed the alarm buzzer goes off. The alarm is a steady buzz, and not beeping. What am I missing? Thanks Steve
 
The old impeller had one finger that was torn but it was pumping water. Where is the thermostat and poppet valve?? I never knew it had those. I will check or replace them if I know where they are. Thanks Steve
 
At slow speeds and up to just a cruising speed the alarm does not go off. Only when full throttle. It makes it very hard to diagnose. Steve
 
I don't believe that model had either a thermostat or a poppet valve.

You said that one fin on the impeller was missing - did you find it?

If not it could have crumbled and worked it's way up the water tube. That could cause a partial obstruction in the tube itself or in the channels of the power head or exhaust manifold.

If you have a good pee stream that may indicate that a potential clog is in the exhaust end of it. Water could well be making it to the top of the block (and out the telltale) but if it's being restricted at the exhaust all that hot water (save what is peeing out) is backing up causing your overheat at higher rpms (when the pump is trying to move the most water).
 
Is there a way for me to blow air through something to see if it is clogged. I had the impeller replaced back in 2009 by a repair shop so I do not know if it had broken pieces or not. The alarm went off a week ago so the first thing I did was to look at the impeller my self this time to see what might be going on. It had a tear on one of the fingers but was not torn off so it came out whole. Could there be a weed or something up past the impeller. The pee stream is very good. Can I back blow anything? Or what would be the easiest way to make sure all is unblocked. Thanks so much Steve
 
I wonder if I took the lower unit off again so that the copper pickup tube was hanging down without going into the water pump housing, could I blow air into the telltail water outlet hole and back blow air through everything. Wonder if that could dislodge anything if there is a blockage. Maybe someone else has a good idea. All ideas are very welcome.........Steve
 
Ok I took the lower unit off again and connected a hose to the block where the telltail hose attaches. Flushed it into a clean bucket and did not see anything come out that would obstruct the flow. I did let it run and filled up a couple of 5 gal buckets. Will take the boat to the lake soon to see if that did any good or not. One thing I was going to mention is this motor has never seen salt or brackish water. Always run in fresh water. I don't think there would be any corrosion to cause a blockage. I wonder if the sensor could be bad?????We are going to run it at the lake with the cover off and I will feel it while it is running at top speed to see if it is truly getting hot. I don't know what else to try at this point. Steve
 
Buy or borrow a thermal laser temp gun so you can check the block temp near the overheat senso/switch when/if it goes off again.
 
Back
Top