Frustrated with 50 H.P. Merc

[HoleSnipe]

Good morning all. A few months ago i posted a message on here about my 1968 4 cylinder 2 stroke mercury outboard and you were all very helpfull in getting it back together and running again. And it still runs but i now have a problem with it staying running. The engine seems to run fine at idle or WOT but nothing in between. I am thinking maybe a vacuum leak but not sure. The only other clue i have for you is that when it is doing this the priming bulb will not get hard. The tank fuel line and bulb are all brand new so i don't think the problem is in these components. If anyone has any ideas on what i might be able to look for i sure could use the help. Hope everyone has a great day and hope to hear from some of you soon.

 

[mellowyellow]

Re: Frustrated with 50 H.P. Merc

assuming your tank is vented properly, sounds like<br />the floats to me. with the cover off, pump the<br />primer bulb and look to see if gas is running out of carbs. <br />the floats may be sticking or not set<br />properly. tap on the side of the bowl with the<br />but of a screwdriver to see if it unsticks.<br />did you remove/rebuild the carbs? if yes, how did<br />you set floats? of course this is one of many<br />possible causes...<br />good luck,<br />M.Y.

 

[steelespike]

Re: Frustrated with 50 H.P. Merc

HS, My guess is some kind of contamination in the carbs or a carb. Dirt or water causing one or both carbs to not respond properly in mid range.<br /> If the motor sat around a lot you should go through the fuel system.Check clean and or repair all components as required.Couldnt tell from youre post if you meant new tank or new fuel line only.If tank is old start there.

 

[ABURTON87]

Re: Frustrated with 50 H.P. Merc

I know the feeling hole snipe i just bought a 22ft pontoon with a 1999 50hp 4 stroke mercury. Took the boat out fishing last night cranks up but has a skip to it. give it throttle it dies you have to punch the throttle for it to go and it will not run over 3800 rpms. while we were fishing i decides to pull the cover check the plug wires to see if they had spark seemed fine not crossed. Figured it had to a bad plug or plugs and possibly fuel filter. So when we got back pulled the plugs 1and 2 were fine 3 was the worst looking and 4 looked a little bit bad so went and got new plugs for all cylinders and got a new fuel filter. Got back put the plugs and fuel filter on took the boat to the water expecting that to fix the problem hopefully. Boy was i wrong didnt change at all so loaded the boat back up brought it back home pulled #3 plug it was wet so with the plug out hooked the wire to it turned the motor over and the plug is firing. Now expecting the worst i went to my parts store to get a compression tester got it back home the fittings would not fit plug hole apparently this motor has odd ball threads. So i didnt get to check it but we didnt turn it over with the plug out and i dont know if i just dont wont to think that the cylinder is droped but it sounds as if it has alot of compression. I just do not undertand this motor maybe has 30 hours on it total all i have heard about the four stroke motors is that they have no trouble at all thats why i bought this boat with that four stroke motor i like to be able to get in it and go not have to work on it all the time . If i wanted to work on a motor all the time i wouldnt have bought it would have just kept my old boat if anyone has any ideas or perhaps some GOOD NEWS that my worst fears of that cylinders being dropped please let me know.