fixed!!!update mercury 1986 25hp

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lizardfish

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Mar 6, 2009
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took boat out today,, fired right up,,let it warm a bit and went up and down the lake for bout 10-15 mins then it bogged down at full throttle,, and died after a few mins it started again and still no power,, let it sit bout 15mins and it fired up again same thing after bout 5 mins it bogged down again,,what should i check now?serial#A955266.......could this be a bad coil?
a bump would be nice....

when i put the muffs on it does run and idles good seems like when it hits the lake and warms up it acts up...


fixed it,was the switch box
 
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lizardfish

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Re: new update mercury 1986 25hp

Re: new update mercury 1986 25hp

i replaced the bulb and cleaned all filters also
 
Plainsman

Plainsman

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Re: new update mercury 1986 25hp

Re: new update mercury 1986 25hp

When it starts to bog down, try priming the fuel bulb and see it that helps. If so then the fuel pump needs to rebuilt.
 
OldMercsRule

OldMercsRule

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Re: new update mercury 1986 25hp

Re: new update mercury 1986 25hp

Plainsman is suspicious about a fuel issue, as am I.

BTW: The fuel pump is part of the carb on that engine.

I live in the PNW where it is very VERY wet, (can't tell where you live).

The first thing I do in a new season is verify there is no water in the fuel tank BEFORE if fill the tank with fresh fuel and 16 oz of oil.

I would look at the fuel separator to see if you have water in it. If so remove the water and check yer fuel tank for water.

If no water check the fuel line and tank fittings, (make sure the bulb is firm with no air or fuel leaks in the line prior to starting it).

If it bogs again pump the bulb as Plainsman states.

If that brings her back to life it is carb and fuel pump rebuild time, (kits here on iboats).

Hope that helps. Good luck JR
 
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lizardfish

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Re: new update mercury 1986 25hp

Re: new update mercury 1986 25hp

i did tear into the carb and it looked brand new so i put it back together,, far as the fuel pump location im not sure about?
 
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steelespike

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Re: new update mercury 1986 25hp

Re: new update mercury 1986 25hp

You may be losing one cylinder.Check spark when it acts up.
If it seems to slow up like its laboring through a weed bed it may be over heating.CAREFULLy touch the head should be too hot to leave your hand on but not so hot it burns you.
 
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lizardfish

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Re: very good new update mercury 1986 25hp

Re: very good new update mercury 1986 25hp

went out today,, runs very good,,, 1 flaw, had it wide open and it bogged,,, let it settle down and after that it ran great,, i think it might have been flooding out at wot,, so if i keep it just under wot, no problems at all,, if u all have any imput on a solution im all ears,, other than that im happy ,was out all day,,, and by the way caught a 11lb bass at lake ozarks ,only fish i caught ,,,thank you all very much
 
M

Merc25XD

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Re: very good new update mercury 1986 25hp

Re: very good new update mercury 1986 25hp

That's some nice Bass...........
 
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lizardfish

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Re: very good new update mercury 1986 25hp

Re: very good new update mercury 1986 25hp

went out again today,,, not so good,,, motor bogged alot,, then before we leave it decides it wants to run good,, i just put a carb kit on it,,does idle better but same problem still exist,,, drove around the lake yesterday and it ran fine,,, seems like when i go to fast to wot loses power sounds like it down shifting or sumthing,, any suggestions r welcome.
 
OldMercsRule

OldMercsRule

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Re: new update mercury 1986 25hp

Re: new update mercury 1986 25hp

The suggestions have already been made above.

These engines are simple. Ya need even compression (over 100 per side), fresh fuel, (without ANY air leaks or water), hot spark for both cylinders, and a clean carb and good fuel pump.

A factory manual would help you as well.

Read them again if you didn't understand them. JR
 
L

lizardfish

Seaman Apprentice
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Mar 6, 2009
Messages
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Re: new update mercury 1986 25hp

Re: new update mercury 1986 25hp

well then thank you for all your help....
 
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rustyh

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Mar 7, 2009
Messages
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Re: fixed!!!update mercury 1986 25hp

was the motor going ummmmmmmmm ...................ummmmmmmmmmm..............ummmmmmmmmmm at wot and running good at about 3/4 just curious i had the same kinda thing happening and have checked for air and spark and at the things listed above
 
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lizardfish

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Re: fixed!!!update mercury 1986 25hp

it ran fine,, it was jus when i went full throttle it would just bog down, sounded like it was down shifting,wich i believe was a cylinder going down, top speed at bogg down bout 5-7.
 
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lizardfish

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Messages
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Re: fixed!!!update mercury 1986 25hp

rustyh said:
was the motor going ummmmmmmmm ...................ummmmmmmmmmm..............ummmmmmmmmmm at wot and running good at about 3/4 just curious i had the same kinda thing happening and have checked for air and spark and at the things listed above
Click to expand...

sounds like maybe a carb prob,, maybe flooding or a jet clogged if its acting up at wot,, slapp a carb kit on it ,if u havent already
 
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