Possible electrical ?

[george dourian]

Hello folks!
I'm new to this so bear with me!
I have a 1971, 50 horsepower Mercury outboard engine. I just recently noticed that after cruising on the water for about 5 minutes (as temp. increases), that it begins to cut back on power. Essentially, i believe that it drops from running on possibly 4 cylinders to 2. I tried changing to new plugs, but with no success.
What could the problem possibly be? Wouldn't mind fixing it myself....
Thanks,
George

 

[Silvertip]

Re: Possible electrical ?

You need to verify that it does or does not have spark on all cylinders when it begins to lose power. Have someone squeeze the primer bulb when this happens. If the engine picks up momentarily you have a fuel delivery problem. Most likely a fuel pump issue. Are sure the engine is not overheating? When was the water pump impeller changed last?

 

[george dourian]

Re: Possible electrical ?

Thanks for the quick reply SilverTip!!
Like i stated on my first ever post, i'm kind of new at this,so I completely forgot to mention on last thread that I did manage to check the plugs, and i believe that cylinders 3 and 4 aren't firing fully (Could be cylinders 1 and 2..not sure) Whatever the case, 2 of the four cylinders are firing fully.
thanks again!
George