just took my boat/motor out for first time; Merc 25hp dies when i try to open it up??

kennyboater

Petty Officer 3rd Class
Joined
Mar 11, 2008
Messages
95
as a few of you know (laddies), I have a 1984 25hp merc XD on my 15ft aluminum. the motor idles great and I can give it throttle until just before I start to plain, but then it cuts out....

as i give it more throttle, it goes fine, then sputters just a little, then cuts out... So sounds like a fuel problem. would it be too much, or too little fuel.

When i first purchased the motor, it had not run in 3 years the guy said.
so i took off the carb and cleaned it with gas and carb cleaner while blowing out all the jets. I changed one of the 2 coils and rebuilt the water pump.

it idles and pumps water fine. So, where should I start? should I purchase a carb rebuild kit?

thanks
 

cannonford57

Petty Officer 1st Class
Joined
Mar 5, 2008
Messages
353
Re: just took my boat/motor out for first time; Merc 25hp dies when i try to open it

your on the right track i think,if i'm not mistaken those carbs have an accelerator pump on them...when they sit they do dry out...if you have a pull out knob that controls both idle and cold start you do....looking straight on at the motor its either a blue or a black stem that depresses when you pull the knob out on the rightside of the carb...a kit may be necessary along with a good soaking....hope that helps
 

kennyboater

Petty Officer 3rd Class
Joined
Mar 11, 2008
Messages
95
Re: just took my boat/motor out for first time; Merc 25hp dies when i try to open it

yep cannon, I have that pull out knob. I did soak the carb when i cleaned it, so I guess maybe a rebuild kit...?

any more opinions?
 

kennyboater

Petty Officer 3rd Class
Joined
Mar 11, 2008
Messages
95
Re: just took my boat/motor out for first time; Merc 25hp dies when i try to open it

any more thoughts? Laddies?
 

kennyboater

Petty Officer 3rd Class
Joined
Mar 11, 2008
Messages
95
Re: just took my boat/motor out for first time; Merc 25hp dies when i try to open it

anyone?
 

kennyboater

Petty Officer 3rd Class
Joined
Mar 11, 2008
Messages
95
Re: just took my boat/motor out for first time; Merc 25hp dies when i try to open it

need some help,

laddies, you around?

btw, i checked the compression on each cylinder, it is just over 120psi on each
 

Neverhome

Petty Officer 3rd Class
Joined
Sep 12, 2004
Messages
86
Re: just took my boat/motor out for first time; Merc 25hp dies when i try to open it

You could have a pin hole in our fuel line. If you do, as you speed increases it will suck more air into the fuel line and collpase the hose. Check to be sure all of your fittings are tight, and there are no holes or cracks. I have seen that happen three times now. Once on my own boat and twice on two others.

Neverhome
 

kennyboater

Petty Officer 3rd Class
Joined
Mar 11, 2008
Messages
95
Re: just took my boat/motor out for first time; Merc 25hp dies when i try to open it

all the fuel lines are new... so there sound not be any holes in them and all my fittings are tight.

this may sound like a dumb question, but there are two smaller lines that run from under the manifold (where the carb connects to the motor) and they run to near the back of the cylinders. what are they and what are they for?

anymore thoughts?
 

Neverhome

Petty Officer 3rd Class
Joined
Sep 12, 2004
Messages
86
Re: just took my boat/motor out for first time; Merc 25hp dies when i try to open it

Sorry, Can't help you there. I have no idea what they are for.

Neverhome
 

flare926

Cadet
Joined
Apr 30, 2008
Messages
6
Re: just took my boat/motor out for first time; Merc 25hp dies when i try to open it

well it sounds like your carbs are gummed up with old gas which turns into varnishand gets thick, what you can do it take them off and either clean them up by using parts cleaner or bring them to any local autoshop and see if they will clean them... you can also get repair kits at any mercury marine dealer.
 

kennyboater

Petty Officer 3rd Class
Joined
Mar 11, 2008
Messages
95
Re: just took my boat/motor out for first time; Merc 25hp dies when i try to open it

thanks flare, above it says that i already cleaned the carbs.

i took the bowl off yesterday and found that there was gas in the float; meaning there is a leak in it somewhere...

would that cause it to die when i try to open it up?
 
Top