Mariner 50 cont beep temp plus loss of top end

daviddustyy

Cadet
Joined
Aug 6, 2004
Messages
16
Please help as I am at a loss with this now <br />I have a mariner 50 1990-91 the boat starts fine it dose not get hot and the oil mix is fine too <br />I have however the continues beep sound coming from the throttle control and like most of the posts it seems the easiest way to get rid of it is to turn the key back a bit without cutting the engine right off (dodgy switch)???<br />All of the connections are clean in the throttle box and also in the engine its self the compression is ok too kicking out 125 on each cylinder I have cleaned the carbs and put in new plugs also if I disconnect the temp wire that comes out of the block it stills stays on but if I disconnect the small black box situated under the starter that also connects to the temp wire the beep stops hooray!!!<br />But the biggest problem is the engine is holding back and I only know this because every now and again on full throttle it seems too clear for a few secs and the boat takes off J is the elec problem causing the lack of power or is it two problems?<br /><br />Any thing im missing here ? <br /><br />daviddustyy@aol.com
 

WillyBWright

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Dec 29, 2003
Messages
8,200
Re: Mariner 50 cont beep temp plus loss of top end

Welcome to iboats.<br /><br />I'd like to get this straight in my mind. Are you getting a beep beep beep, or beeeeeep? Beep beep beep is an oil warning, beeeeeeep is an overheat warning.<br /><br />The alarm continues if you disconnect the overheat sender and that should indicate that it isn't the problem (still could be, but let's assume it's not). The black box is the warning module. If that fails, you can get a constant beeeeeeep. There should be a couple of wires coming out of the bottom of your oil tank. Disconnect one. If it's a beep beep beep and that stops, then the float in the oil tank probably doesn't float anymore. If that's the case, you need a new oil tank.<br /><br />Right now I'm leaning toward a bad warning module, but try the oil tank test first.<br /><br />I don't think you have a feature that would limit the RPMs if you get a warning. I think your running issues are separate from the alarm.
 

daviddustyy

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Joined
Aug 6, 2004
Messages
16
Re: Mariner 50 cont beep temp plus loss of top end

its not a beep beep its a beeeeep and i can stop it by disconnecting the brown wire coming out of the little black box<br />as for the poor top speed is there anything on the ignition switch that could cause this because i did start to take the throttle control off the boat but it was too choppy at sea so i went back in to finish the job off on land and it seemed a little better on the way back in not sure if i had disturbed something as it was ok for longer period.
 

daviddustyy

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Joined
Aug 6, 2004
Messages
16
Re: Mariner 50 cont beep temp plus loss of top end

also the engine is pumping water ok and not getting hot so i guess it the module <br /><br />but the real bummer is not being able to go flat out <br />could this also be cause by bad tank breather or water in the fuel?
 

ronmold

Petty Officer 1st Class
Joined
Sep 8, 2003
Messages
240
Re: Mariner 50 cont beep temp plus loss of top end

When you say the problem "clears" for a few seconds is it like someone throws a switch and the motor just takes off? Also does the motor run rough and shake when you open the throttle and it doesn't go? I repaired this problem on my 175 by replacing the switchboxes. Is the wire you disconnect brown(tan)/blue? If so it is the oil warning module and if it gives a solid buzz and not beep beep as it should it is defective.
 

daviddustyy

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Joined
Aug 6, 2004
Messages
16
Re: Mariner 50 cont beep temp plus loss of top end

the wire i disconnected is brown(tan) <br />switchboxes???<br />yea it is sort of rough when you open it up but idle is fine <br />but yes that is what its like when you say its like flicking a switch because its like the engine is governed to half its rev range i cant get it to screem if you know what i mean.
 

daviddustyy

Cadet
Joined
Aug 6, 2004
Messages
16
Re: Mariner 50 cont beep temp plus loss of top end

thanks for you help by the way!<br />whats the switchboxs and where are they located ?
 

daviddustyy

Cadet
Joined
Aug 6, 2004
Messages
16
Re: Mariner 50 cont beep temp plus loss of top end

Many thanks to all of you but im still stuck :(
 

ronmold

Petty Officer 1st Class
Joined
Sep 8, 2003
Messages
240
Re: Mariner 50 cont beep temp plus loss of top end

not sure on a 40hp but it is where the red & blue stator wires & trigger wires go. It has lots of terminals on it.
 
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