Evinrude 50hp stroke (1989 i think) only fires on one cylinder

yabble

Cadet
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Mar 28, 2011
Messages
6
Ok i have an evinrude 50 hp stroke engine has been running absolutely perfect till last weekend. on the pontoon started it up and i sounded rough, like it was on one cylinder i tried giving a little throttle but it just stalled. I tried to start it again but the starter motor wouldn't turn the flywheel like normal, it would do 3/4 of a revolution then stop and sruggle then do another 3/4 this would go on and on. I thought maybe my battery was dead changed for a charged one and still the same problem! so I take the boat out the water get it hooked up to my car battery with jump leads and it turns over fine even get it started mut it only seems to be running on bottom cylinder.

What i have checked :

Carbs, i changed them round also to eliminate from investigation.

Plugs and all things relating to plugs and again swapped all around and still have the same problem.

Fuel filter and lines, again swapped lines around and still nothing.

When i start the engine with everything connected it starts, if i remove the top plug cable it sounds a little different but still runs if i remove the bottom plug keeping the top plug connected the engine stops running.
something i also noticed is when water starts to come out of the pee hole the engine seems to drop revs and stall.

Sorry for the essay but really getting frustrated! hope someone can help.
 

yabble

Cadet
Joined
Mar 28, 2011
Messages
6
Re: Evinrude 50hp stroke (1989 i think) only fires on one cylinder

must add since hooking up to car and turning over the engine flywheel feels light again, like it should.
 

emoney

Commander
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Jul 19, 2010
Messages
2,551
Re: Evinrude 50hp stroke (1989 i think) only fires on one cylinder

Better do a compression test. Start there and then post your results. Did the motor overheat before?
 

yabble

Cadet
Joined
Mar 28, 2011
Messages
6
Re: Evinrude 50hp stroke (1989 i think) only fires on one cylinder

no dont think so! will do compression test tonight if i can. what should it be ?
 

emoney

Commander
Joined
Jul 19, 2010
Messages
2,551
Re: Evinrude 50hp stroke (1989 i think) only fires on one cylinder

It varies, but I'd say somewhere around 125. However, the two cylinders should be within 10% of each other, regardless. You should check compression first, and then if that's good, then do a spark test, but post your results and help will be forthcoming.
 
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