1989 Mercury 25 hp hard cold starting

Briwil

Cadet
Joined
Apr 19, 2013
Messages
18
I'm relatively new to Iboats and to boating and would appreciate some suggestions for a solution to a starting problem that I have. I recently purchased a 1989 25 hp 2 stroke Mercury outboard along with a boat and trailer. The motor is clean and looks well cared for. The previous owner run a long fuel line from the motor in the stern to the bow of the boat where he placed the fuel tank. When I initially tried to start the boat, I noticed that the fuel line connection (tank end) was not making a tight fit with the tank connection and the bulb was not staying firm. When I tried to start the motor, it took 12 to 15 pulls to get it going. I replaced the connections at the tank end and now the bulb stays firm. However, I still have trouble getting it started (12 to 15 pulls) after it's been sitting for several hours or overnight (even when the outdoor temperature is extremely hot such as 90 F). However, it starts first pull if it's been running within the past 20 to 30 minutes. Examination under the cover does not show any leaks of fuel and it appears very clean. I have tried starting it with full choke, partial choke and no choke but to no avail. I have good compression and it runs very nice at all speeds when I take it out. It's frustrating to go out fishing early in the morning because it takes so long and so much effort to get it going. Any suggestions as to what I can do would be greatly appreciated.
 

windy5849

Petty Officer 1st Class
Joined
Aug 12, 2010
Messages
237
Re: 1989 Mercury 25 hp hard cold starting

According to the owners manual for my 1990 25hp EH model,you rotate the choke knob fully clockwise,pull choke knob out to prime engine,push choke knob in and try to start.I have pushed the knob in and out a few extra times if the engine was stubborn to start.Each in and out motion shoots extra fuel into the engine.Hope this helps.
 

Briwil

Cadet
Joined
Apr 19, 2013
Messages
18
Re: 1989 Mercury 25 hp hard cold starting

Thanks Windy: I have tried turning the knob fully clockwise and then pulling the knob out and back in. Today, I tried pulling the knob out and back in twice but there is no change. It just seems to always take 12 or 15 pulls with nothing happening and then it just catches on. It runs great once it has started. However, I'm not as young as I used to be and my arms get tired from pulling. If anyone has any other suggestions , I'd really appreciate it.
 

TheCat1212

Cadet
Joined
Feb 28, 2013
Messages
26
Re: 1989 Mercury 25 hp hard cold starting

try a little starter fluid into the carb before you pull. could be the primer pump is bad and not shooting fuel. after a while it will have sucked enough in on it's own to start.
 

cincinnati

Recruit
Joined
Jul 10, 2013
Messages
3
Re: 1989 Mercury 25 hp hard cold starting

try a little starter fluid into the carb before you pull. could be the primer pump is bad and not shooting fuel. after a while it will have sucked enough in on it's own to start.

Yep, seems like a lean condition. If the primer is working correctly, you should be able to hear it hiss softly each time you pull the choke out. There is a repair parts kit listed for the primer/injector, which includes a new diaphragm, gaskets, etc..
 

Briwil

Cadet
Joined
Apr 19, 2013
Messages
18
Re: 1989 Mercury 25 hp hard cold starting

Thanks The Cat1212 and cincinnati. I will look into purchasing a primer/injector repair parts kit from my local Merc. dealer. In the meantime, I'll keep some starter fluid nearby. Briwil
 

Mi duckdown

Commander
Joined
Apr 14, 2007
Messages
2,575
Re: 1989 Mercury 25 hp hard cold starting

DON'T use starting fluid. hard on bearings, use pre mixed gas if you have to.
 

Briwil

Cadet
Joined
Apr 19, 2013
Messages
18
Re: 1989 Mercury 25 hp hard cold starting

Thanks , I'll use pre mix gas instead. I really appreciate all the help. This is a great forum.
 
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