Mercury Outboard problems...HELP

[LaXCarp]

Alright guys, looking for a little insight here as I dont have too much knowledge about outboards.

I purchased an alumacraft with a 1998 Mercury 25hp, w/ electric start. Yesterday was my first time on the water with it since purchasing. After I put in, the engine started right up with the electric ignition, no choke needed. I idled around for about 10 min, at very low speed getting the engine warmed up. Afterwards, I decided to open her up a bit and start heading down the lake, about 30 sec into this trip the motor began bogging down and died completely.

At this point I didnt think too much of it just, maybe just not warmed up yet. I tried restarting the engine with the electric ignition, and it would only "click", the motor didnt turn over at all. I eventually got the motor going again manually, but only with the choke pulled all the way out. When i would increase the throttle at this point, it would bog down and either die or run a little bit but not sounding very good. At any point if I pushed the choke back in the engine would stall.

I eventually got towed back into the landing (luckily a friend lives on the lake) and loaded back up. I drove the boat home and decided to push the electronic ignition button to see how it reacted...the motor started right up. I am hoping that was a freak thing, but I plan on getting the motor back into water this weekend to see how it goes this time...any info you guys can provide me with will be greatly appreciated!!

[Surface Tension]

Its starving for gas. Check the fuel line and bulb for air leaks and that its on with fuel flow in the right direction, there'll be and arrow in the bulb. Vent the gas tank, Replace fuel filter. You might end up cleaning the carb. Fuel pump could be weak and needs new a rebuild also.

[eurolarva]

Sounds to me like you overheated. When the motor overheats metal expands and stops the pistons from moving. After it sits for awhile and cools down the metal contracts and you are able to run it again. I would put it in a garbage can with water and see if it is spraying water out. Also check your plug tips and see if they are dry or oily.

[boatfixer]

The part about bogging down then stopping, then not turning over concerns me too. Compression check would also be a good thing to do at this point.

[minneman]

Was the vent open on the gas tank?

[Kyle Sandberg]

Oil levels. Just a reminder and make sure they're not to low to make it seize up.

[Surface Tension]

I read you post over again and as Euro pointed out you could be overheating. After the click you went to start the engine with the rope, was it stiff?

If you take this back out be sure theres water coming out of the tell tail, if there isn't don't run the engine.

[Valv]

Besides the cause of the problem do not ever start motor out of the water unless you have hose connected and water running through motor.

It's enough few seconds of running dry for the water pump impeller to melt and not pump any water, which is what I assume it happened while checking motor before buying.

Be sure there is a good tell tale stream from back of pee hole, if not stop and have it serviced.

[LaXCarp]

The motor didnt seem overly stiff when I started it manually, it just seemed like it wasnt getting gas correctly. I made sure to notice if it was peein, it was but it seemed to be more of a steady spatter, then a steady stream.

I got in touch with who I bought it from, he mentioned he had it winterized at a dealer and he said it could be from the fogging oil that was sprayed in there. He also said I might not have the neutral lined up correctly for the electric start to work, but I do not believe that was the problem. Any ideas why the electric start would work one minute and not the next, and then work again?

[boatfixer]

First of all, fogging oil won't cause an engine to die out especially after it has already run for several minutes. I could see where they are hard to start after being overfogged.Second, When you say the starter "clicked" were you able to tell if the starter was trying to engage the flywheel?

[eurolarva]

Battery could be going bad or starter connections are dirty or loose or corroded. I would put the motor in a garbage can with water and test it real good. Let it run for 10 minutes and test the water coming out of the telltale and verify it is very warm. Would not hurt to replace the impeller just for peace of mind.

[Valv]

Quote:

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Would not hurt to replace the impeller just for peace of mind.

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That would have been the 1st thing I'd done after purchasing a motor.

There could be many issues, as ST said I would bet carb needs cleaned, when you need choke to run motor it means mixture is too lean, a carb kit will fix problem.

No start electric could have been shifter not set in neutral correctly (maybe just bumped a little) or also starter gear binding.

I wouldn't trust the word of anybody unless you understand exactly what they are talking about (...geesh, this means my replies too... ) and I strongly suggest you take it to a shop to have it checked.

[boatfixer]

If the solenoid "clicks" then it is not an issue of the neutral switch not being lined up. You won't have power going to the start terminal of the solenoid when you push the button. Valv probably has the best suggestion so far, if you are at all uncomfortable, take it to a reputable shop.

[LaXCarp]

Just got back out from the water and things seemed to be going much better. Tonight the engine started up the same as it did the other day, no choke and everything seemed smooth. I went through the same cycle of running around a bit at low speed, when i started opening it up, the engine would bog down and i would have to throttle down to keep it from dying.

After this happened, it ran best with the choke pulled out and would die when I pushed the choke in. I managed to get back to the landing and decided to just let the motor run for a good 15 min, until it seemed to sound pretty smooth.

I decided to head back out on the water and the first few times I throttled up, it would bog down but not to the extent previously. I noticed the longer I was letting the engine run, the better the pee stream was coming from the engine. It seems if that might have been clogged a bit.I got her up to running speed and went around the lake a few times at full throttle hopin to burn everything out and clean it out a bit. After this the engine seemed to be running smoothly with no problems.

I wonder if I just had a case of the carb being gummed up a bit and it needed to get some of it burned up. Today I didnt have any problems with the electric start as well. Thanks everyone for the help!

[Valv]

Ok, great news.

Now listen to US carefully.

Get a new fuel tank of gas and add double dose (read can instructions) of Seafoam with the oil mix.

Then while you have boat off duty (for few days) take it to a mechanic and have him change the water pump impeller.

You will not regret you did both.

[boatfixer]

Cool! I'll second Valv, get the water pump changed! Cheap insurance

[LaXCarp]

The current tank of gas I am running through has seafoam in it already, should I get a new tank anyways? How advanced would it be to change an impeller? I would like to do this myself as my funds are limited being a college student. If i get a schematic diagram or maybe some instructions I think I would be able to figure it out. If you guys strongly insist on having this done professionally I guess I will. Thanks again for all the insight guys, what a great website

[boatfixer]

If you plan on having this motor for a for while, buy yourself a service manual. If you have even basic mechanical skills, this is a relatively easy job to do. Besides, you will learn how to perform routine maintenance, as well as trouble shoot and repair other problems you may have in the future. A manual will "pay" for itself in no time. Such as taking it to a shop to have the pump changed. Good luck!

[DrKen]

I've got basically the same motor, a mariner 20hp by merc and have had the same problems. First check the fuel line, does the bulb get hard and stay hard. If it does the chances are you have a clogged main(high speed) jet. That means you have to take the carb off and clean it. It would be a good idea to get a carb kit and do the rebuild at the same time. Note how many turns are on each adjusting screw by turning all the way in from where they are set and then removing them. When you put it back together you will want to put them at the same setting. take the carb off, remove the bowl and drain the gas. Remove the float, unscrew the adjusting needles, remove the jets, clean with a carb cleaner and a wire or needle, reassemble, check your float height at the end. Readjust high and low speed needles( should be about 2 full turns out from closed). Then start the motor and adjust the low speed screw at an idle to the highest idle, rev the motor and adjust high speed screw to highest rev and you are set. When you get it under load on the water, you may need to readjust the low and high speed screws. It's simple to do. This should fix the prob.

[DrKen]

Also, these motors have a thermostat on the water flow. When you first start them they may not pee much at all but then as the motor warms up and you rev it it will really put out the water. Also there is a fuel filter on the fuel inlet by the carb. Make sure you clean this as well. Good Luck. These are great motors and easy to maintain.