81 mercury thunderbolt 40hp tell tale info

info404

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in the past i've found a wealth of info in this forum. so this is the first time i could not find an answer on my own and look to your expertise in helping me. my outboard motor ser# starts with 599, i recently installed new impeller, fuel pump, prop. my tell tale does not work, the lines run from the tell tale, of course ,to the fuel pump houseing. is that right? its what it shows in the manual also. checked it up down all around and it seems if it was to work it would be running water directly over the fuel pump. which i guess, if the diafram ripped it would flood my engine with water. is it possible this model isn't supposed to have a tell tale? if so, why is it there, to vent the fuel diafram?? i don't get it, please help figure out something that i must be missing. thanks in advance...04
 

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Re: 81 mercury thunderbolt 40hp tell tale info

Mercury did go through a few years where they routed the water flow through the fuel pump. For fuel cooling purposes I suspect.

The blue lines on attached diagrams are water lines (red are fuel lines). Check the water lines for blockages (bugs, debris).

You may also have a thermostat and poppet on that motor. Might be a good idea to inspect them, as they -might- interfere with telltale flow. Not a bad idea to look at them periodically anyways.
 

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info404

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Re: 81 mercury thunderbolt 40hp tell tale info

WOW, that is exactly what i needed. i thank you very much. wish i had that diagram to begin with. again thank you...04
 

info404

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Re: 81 mercury thunderbolt 40hp tell tale info

took a look at it again thx to the diagram you sent, followed all the water lines and finally found the block in the fuel pump houseing. tell tale pees like a pro now. thx...04, oh yeah, i also noticed that the houseing does not flow over the fuel pump diafram, its a separate channel in the houseing
 

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Re: 81 mercury thunderbolt 40hp tell tale info

Glad to hear you got it sorted out...

Pay it forward.

Happy Boatin :)
 
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