Michael LaSalle
New member
I have a 89 mercury 45hp classic fifty that is only running on three cylinders.
I have just went through the whole fuel system with all new everything. New spark plugs. Compression checks out at 125. It starts right up an goes ab 18-20 mph in the water, but seems to not quite reach 5000rpm. It seems a little gutless. I got home an checked the spark plugs an the bottom cylinder plug is still new looking while the other three are a normal browned/black. #4 is lightly wet with oil, so i know its getting fuel.
So i switched the number 3 and 4 cylinder plug, wire and coil and ran it again. Still no fire on bottom #4 cylinder. Funny thing is that cylinder shows a spark when using a spark checker
Something is causing it to get a weak or intermittent spark on that bottom cylinder or causing it to not get spark under load. What do yall think
I have just went through the whole fuel system with all new everything. New spark plugs. Compression checks out at 125. It starts right up an goes ab 18-20 mph in the water, but seems to not quite reach 5000rpm. It seems a little gutless. I got home an checked the spark plugs an the bottom cylinder plug is still new looking while the other three are a normal browned/black. #4 is lightly wet with oil, so i know its getting fuel.
So i switched the number 3 and 4 cylinder plug, wire and coil and ran it again. Still no fire on bottom #4 cylinder. Funny thing is that cylinder shows a spark when using a spark checker
Something is causing it to get a weak or intermittent spark on that bottom cylinder or causing it to not get spark under load. What do yall think