alarm sounder

mrccure

Cadet
Joined
Dec 3, 2007
Messages
7
1988 Mariner 150. had both intermittent and then solid sounder and lost tell-tale water outlet. changed impellar and both thermostats, have water tale back, still a little warm on the stream but the sounder is still intermittent. oil resevoir was low and filled back up for another check, motor sticker says to fill up and run engine for 5 minutes until sounder shuts off. in fear of overheating engine, hesitant of running for that time especially when in alarm condition. any other suggestions.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,089
Re: alarm sounder

That motor's thermostats likely open at 140 degrees. Put your hands on the head. They should be hot to the touch, but not to the degree that it will burn you. The overheat sensor is on one of the heads. It will short to ground to indicate overheat. You might test it with a continuity meter, when the engine is cold. If it has continuity to ground, when the motor is cold, it is faulty.
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: alarm sounder

When the intermittent (oil alert) goes off, you need to stop and mix oil in your main fuel tank at 50:1 before you go one inch further.

I would guess you've fried yer motor by now. Looks like you have multiple maintenance related failures in oiling and cooling.

hope it helps
John
 

Windykid

Lieutenant Junior Grade
Joined
Apr 17, 2007
Messages
1,177
Re: alarm sounder

I agree with chris! Might want to check compression just to make sure all insides are good.
 

mrccure

Cadet
Joined
Dec 3, 2007
Messages
7
Re: alarm sounder

I changed both thermostats and the impellar, have water back. I checked the oil resevoir and was low, filled back up and did the oil line bleed that the manual had said, loosen oil cap 1.5 turns until oil pump makes cap leak. that went good. Engine started up very well and had smell of two stroke oil burning and bluish oil burn from motor exhaust, as well as oil residue on the water drainage from the exhaust from propellar. motor idled very well at low rpm, if low compression in one or multiple cylinders, would think engine would run rough or miss, not at all the case. will check compression any ways for verification, could the cap that has a sensor in the engine resevoir be causing the sounder to go into alarm. is there another sensor after the resevoir that could cause an alarm? after changing impellar and thermostats, manual said to run for short while to clear sounder, engine did not get super hot after several minutes of idling speed and water tale was much better. is there another location to check for oil mixture after the resevoir?

any continued help is very much appreciated, still reading and researching threads.
 

gss036

Commander
Joined
Jan 18, 2003
Messages
2,914
Re: alarm sounder

You have a couple of wires that come off the oil tank on the engine. They are probably connected by bayonet fitting along side of the engine, disconnect them and see if the alarm stops. If so the fault is in the magnetic pick up in the tank. If not, then check the wires from the oil pump sender, trace it around to the connection on the junction box on the engine and disconnect the ground (black wire), if it stops one can assume the sender is bad.
You have a couple of clear lines from the oil pump/fuel pump that send the mixture to the carbs, the fuel oil mixture should be the color of the oil, in most cases,blue. The OEM manual gives a trest procedure to check the oil flow from the pump, read it and and check if you are still in doubt.
 
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