Fuel issue? 45 hp Mariner

[Carlson625]

I am new to the forums but I have been looking through everyone that I can find hoping to find my issue. I've tried several of the recommended repairs with no luck.

Here's what I got going.

1987 45 hp mariner outboard 4 cylinder. It starts up fine, but dies shortly after. It will start right back up after priming the ball again but starts to sputter unless I keep tapping in the choke, which then I can keep it going. I did notice when squeezing the primer ball when its fairly firm that fuel comes out in a steady stream from both carbs out of the slotted screw in the upper right corner. I have had the carbs gone through a few years back by a marina and has sat since. So I took them apart, cleaned them out and things look good inside. Floats and needles look new with no buildup on them. So I put a new fuel filter and hose clamps on all of the lines (had all zip ties before). It had a fuel filter with just a metal screen before, and I now used a automotive clear plastic one with the yellow paper insert (is this ok?). I hooked everything back up, put the muffs on it, primed it, and it fired right up. The primer bulb did get firm, but one pump past when it was firm still shot fuel out of both carbs (i figured I'm just pushing fuel past the needles??). with it running I watched the fuel in the filter keep draining until it was about empty and then it would die again. I could prime it back up again and the filter would fill up and it would run until it was empty. when i gave it throttle, a little bit of fuel would sprinkle down into the filter. I didn't have to choke it to keep it running like i did before, but that had happened when I was on the water, not on muffs. The fuel tank and primer fuel line are pretty old themselves (lines look okay), but if i disconnect the quick connect fuel line from the motor and prime the ball, it gets rock solid, so I would think that means no air leaks on that end?!? It is a 2 piece hose. One end goes from the fuel tank to the oil auto blend pump, and then another hose from that pump to the motor with the primer ball on it. I know absolutely nothing about the oil blender, and I would not object to taking it out if that could have anything to do with it.

Plugs look good, I have never replaced them though. The plug wires go right from the coils to the closest plug in order from top to bottom. I see the firing order is 1-3-2-4. Should any of the plug wires cross?
It seems to run fine when its got fuel, and all plugs have spark so I would think more of a fuel problem.

The minute i tried to give it any throttle out on the water it would fall right on its face dead. I could prime it and it would start up again and then die shortly after.

I have not adjusted fuel/air mixture not thinking that it was a problem. (and that I'm not quite sure how to on these, no manual)

Any ideas?

Thanks,
Nic

 

[Bill kubiak]

Is your fuel coming from a removable fuel tank, if it is, Is the vent on the fuel cap on the fuel tank open??? I would not use an auto fuel filter on a marine engine. Auto fuel pumps work on a higher pressure then outboard fuel pumps.
You can check the fuel pump by disconnecting the line from the pump to the carbs and have someone give the starter a few cranks and see if fuel is squirting out, if not, there is your problem. When you troubleshoot you check one thing at a time and it normally it is something easy that you missed

 

[Carlson625]

I now have put a new primer ball and new tank with the vent open with new gas. I switched back from the auto fuel filter that I had on. It starts up relatively quick when primed. Idles fine with muffs. Give it some throttle and let it run as is and it will die after 5-10 minutes. Most of the time when it dies, the fuel filter looks almost empty. Prime it up and it fires right back up and will idle fine until I give it some more throttle. Only had it on the muffs though. Fuel is coming through the pump, but it doesn't seem like enough to keep up when giving it throttle.

 

[Carlson625]

I disconnected the fuel line coming out of the pump, and there is definitely fuel coming through. So I tried adjusting the fuel/air idle mixture screws. I seated them both and backed out 1.5 turns on each carb, and the motor wouldn't start at all. I seated the screws again and came out to about 1 turn, and then I got it to run. I tried adjusting the mixtures while it was running, but i didn't hear a change in how it was running as i set it for more fuel. Isn't it supposed to bog down at some point and then set it in a quarter turn from there? I was trying to adjust it and it eventually it flooded and died and I gave up for the night. I took the plugs out for it to air out and I will give it a try another day.

Am I adjusting these correct?