86 evinrude 150 alarm

repair man

Seaman
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May 7, 2010
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59
E150STLCDC has a new impeller and after 20 to 30 min. of run time the constant alarm goes off. At this point it runs bad. could the vacum switch which is NLA cause this situation. Thanks in advance.
 

Joe Reeves

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Re: 86 evinrude 150 alarm

The vacuum switch could "activate" the alarm BUT it could not be the "cause" of the alarm.

If the water pump is functioning perfectly.... and you're sure of that, the only other "cause" of that steady constant horn alarm would be either "Swollen Water Deflectors" that are located in the water passages between the cylinders, OR a sticking "Anti Siphon Valve" which would be located at the hose connection of the built in fuel tank.
 

emdsapmgr

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Re: 86 evinrude 150 alarm

A vacuum switch will signal the horn to turn on constatant at high fuel vacuums. Usually high vacuum occurs at the upper end of the WOT throttle range. Not usually at cruising or idle speeds. Joe has offered a couple of important things to check.
 

emoney

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Re: 86 evinrude 150 alarm

Confirm the temp on the heads by using a digital infrared thermometer. These can be had at Harbor Freight for $30.00 and are very handy to own.
 

repair man

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Re: 86 evinrude 150 alarm

Thanks for all your help. I will check temp. in test tank with infared. Can someone tell me more about the "swollen water deflectors" please ?
 

repair man

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Re: 86 evinrude 150 alarm

Found star side temp sensor wire is pulled out of sensor. Fuel leak at filter and fuel runs past the primer bulb and back into tank. It has 2 tanks and Im going to check and eliminate anti-siphon valves.Going to replace water deflectors also because several people have tried to fix this and the owner has a big trip planned for the weekend. Would like to change 1 thing at time but I dont have time. I notice the temp sensor is NLA, shocking.
 

Joe Reeves

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Re: 86 evinrude 150 alarm

Thanks for all your help. I will check temp. in test tank with infared. Can someone tell me more about the "swollen water deflectors" please ?

This is obviously a lower hp engine BUT it shows the general location of the deflectors. Their purpose is to deflect the flow of water to its proper flow. When (if) the deflector(s) become swollen, the water flow is restricted, usually to a point where the flow of water is insufficent, leading to overheating.

85_25hpDeflectors.jpg
 

emdsapmgr

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Re: 86 evinrude 150 alarm

Water diverters.jpg A picture of a properly-placed water deflector.
 

repair man

Seaman
Joined
May 7, 2010
Messages
59
Re: 86 evinrude 150 alarm

This is obviously a lower hp engine BUT it shows the general location of the deflectors. Their purpose is to deflect the flow of water to its proper flow. When (if) the deflector(s) become swollen, the water flow is restricted, usually to a point where the flow of water is insufficent, leading to overheating.

85_25hpDeflectors.jpg

Thanks so much!!
 
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