Mercury 1996 60 hp running only on middle cylinder

[Andrew Japatul]

I believe Ive checked or replaced everything and sill no luck. It will run on the middle cylinder only with throttle advanced. Started with fuel pump. next to carb clean and rebuild. Replaced coils. Checked compression and got 110/110/105. Replaced reed valves. Checked timing. Ensured the needle in the carb was seating properly. Ensured there was sufficient spark. we are stumped

 

[Chris1956]

Gee, if you have fuel, compression and spark, maybe the spark plug wires are arcing to ground, or you are getting water in the cylinders that don't fire. That is if they are not flooded with fuel.