81 mercury 20hp no power under load

[Oatsman1]

I have a canadian made 1981 mercury 200 (20h.p.)that revs up fine when not in gear but when I try to take off in gear the motor sounds really throaty (bogging down)and has no power at all!Iwas told by a friend of mine that maybe the fuel line might have a leak in it,sure enough it had a very little pinhole leak on the out end of the bulb so I replaced the hoses and reclamped it.Would this be the solution to my problem?I want to take my boat down the mighty mississppi but i don't want to break down and end up in New Orleans.(he he)Oh yea I had rebuilt the carb and put new plugs in when this problem started but to no avail that didn't fix it.Could this also be caused by an electronic ignition problem.Just looking at or for all options. Thanks guys,Dave

 

[JB]

Re: 81 mercury 20hp no power under load

Howdy, Oatsman.<br /><br />Yes. You are probably making power with only one cylinder.

 

[Oatsman1]

Re: 81 mercury 20hp no power under load

JB, I have another one of these motors that I have been using for parts,should I take one of the electronic boxes off and try switching that?Like I say it runs real smooth in neutral.You don't think it is a fuel line prob?sorry for all the stupid questions.

 

[papasage]

Re: 81 mercury 20hp no power under load

pull plugs check for spark while plugs out check for compression. if you dont have a compression guage hold finger over plug hole while some one pulls the crankrope or turn the starter . this will tell if there is compression you can tell if the two cylinders are about the same . you cant tell if one ctlinder isnot working when idlling.just when it is in gear.changing parts frome an old motor want tell you anything unless you know it is good .