2001 25 mercury stalling

merctoons

Cadet
Joined
May 9, 2009
Messages
12
25 horse outboard motor will run fine in idle, low and high speeds for a few minutes after pumping primer bulb, then will die and won't start till I pump primer bulb again, then starts right up, runs fine again for a while and stalls again. Is this a fuel pump or carb problem? Thanks.
 

maciejl

Cadet
Joined
Mar 30, 2009
Messages
28
Re: 2001 25 mercury stalling

both
buy diaphram kit for fuel pump and gasket kit for carbs. Clean and change them. This is what I would do first.
 

merctoons

Cadet
Joined
May 9, 2009
Messages
12
Re: 2001 25 mercury stalling

put in new carb kit and fuel pump diaghram, went to start it and started up, ran a few seconds and died, messed around choking it and priming and would fire once in while and even run a few seconds and quit.Now won't start at all and have oily mix running from impeller. checked plugs and are oily black. Have i flooded it badly or other issue?
 

dleve

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Joined
Jun 15, 2003
Messages
6
Re: 2001 25 mercury stalling

put in new carb kit and fuel pump diaghram, went to start it and started up, ran a few seconds and died, messed around choking it and priming and would fire once in while and even run a few seconds and quit.Now won't start at all and have oily mix running from impeller. checked plugs and are oily black. Have i flooded it badly or other issue?

I have this same problem. Rebuilt the carb and fuel pump with new gaskets and diaphragm and got it to start but it is only running a short while before it stalls. If you keep squeezing the primer bulb it seems to run fine. Any advice?

Thanks,,,
 

Bait Me

Cadet
Joined
Jul 30, 2009
Messages
24
Re: 2001 25 mercury stalling

I am having the very same sequence of problems. I have rebuilt the carb/fuel pump, bought new gas tank with new gas/additives, replaced fuel filter) and still stalling. From what I have read from other posts here my next step should be to check (and replace) anything leaking air in the fuel line from the tank to the carb (fuel line, bulb, fittings, etc.). I have bought a new 5' length of rubber fuel line and I plan to bypass the entire fuel supply line from the tank to the carb with the new line and see if I can start ruling things out. Does anyone see any problem with doing this? I guess I will have to find a way to prime the line somehow.

How did you all make out? (I know this is an old post that I am replying to and you may not be tuned in).

I will let you know how I make out.

Any other advise / suggestions from anyone is much appreciated.
 

redmist

Cadet
Joined
Oct 19, 2009
Messages
10
Re: 2001 25 mercury stalling

I think I have the same problem with my 02 25hp
 

will941s

Chief Petty Officer
Joined
Oct 1, 2007
Messages
540
Re: 2001 25 mercury stalling

When you buy the fuel pump kit it should have came in a set with the carb rebuild kit. It sounds like after you rebuilt the fuel pump it's pumping way more fuel then the carb it set for. If you have the motor serviced in the past and the fuel pump was getting weak it's possible that the tech linked and synced the motor and it ran just fine, with the fuel it was getting. Now you rebuilt the pump and it's pumping a whole lot more fuel, causing the motor to flood out and it can't burn the fuel fast enough, thats why you have the gas/oil residue. Either get a manual and adjust the carb according to spec or take it to a shop and have them perform a link and sync. Thats all you need to do and it will run just fine.
 

dleve

Cadet
Joined
Jun 15, 2003
Messages
6
Re: 2001 25 mercury stalling resolution!

Re: 2001 25 mercury stalling resolution!

Fixed! Thanks to Baitme, I went back and checked the new gasket between the carb and the engine. The vacuum port on the carb did not have a hole in the gasket. I punched a hole in the gasket and reinstalled it and the motor runs like a champ. The rebuild kit I originally used was a mercury rebuild kit for my engine so there must have been a mistake in manufacturing it or putting the kit together at the factory...frustrating!
 
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