2003 8HP Runs Poorly

[KBNJ732]

2003 8hp Mercury. Having issues with motor performance . Motor seems to be running on only 1 cyclinder as she is just slow. When i originally got the motor it was alot faster but did show issues as it woul kick in and out of full speed whenever she felt like it. Motor eventually would not start for me after one of my drifts and had to get towed in. Since then i had a mechanic take a look and said it was the stator. So now the motor starts right up but again is slow. Motor will start off top plug only. Replaced coil with same result. Also transferred trigger wire to bottom spark and it will not start but seems to back fire. Any ideas on what can be going on ? Im assuming switchbox but y the back fire off the good trigger wire on the lower cylinder . Multiple issue ?

 

[GA_Boater]

KBNJ732 Welcome.

This is your thread. Posting in old threads seldom works to get advice.

 

[Scott Danforth]

welcome aboard

what is compression on both cylinders?

do you have spark on both cylinders?

only one carb, so if its running, you theoretically have fuel.

however if you have compression and spark, then you have a fuel delivery issue (plugged carb) not delivering enough fuel

the answer to the first two questions will be the clue to what is going on.

 

[tpenfield]

:welcome:

We do not allow swapping for spark plug wires on engines, because it causes backfires If I understand correctly, you put the top wire on the bottom cylinder :noidea:

What that will do is the bottom cylinder will fire when it is at the bottom of its stroke (not the top as it should be).

Follow Scott's advice and go through the basics. You could always test your 'running on 1 cylinder' theory by running it with the bottom spark plug wire disconnected to see if it runs the same.