1999 Merc 8hp 2-stroke sputtering

[Stoney54547]

This motor starts first pull and idles perfectly. If I give it throttle, it boggs down. I've cleaned the carb, fresh gas, and new plugs. It smokes like crazy when I give it gas as well as sputtering and bogging down. I've played around with the jet by backing it out 1 1/2 turns and it gets a little better at about 3 turns out. I'm lost.

 

[Mi duckdown]

What oil ratio? 50:1? Sounds like you need to rebuild the carb and fuel pump

 

[Stoney54547]

Thanks Mi duckdown. I had the carb off. I sprayed every hole and orifice. I ran wire through the small holes in the jets. All gaskets and washers, needle, float and associated parts looked brand new when I was done. I'm using fresh gas at 50:1. I saw no damage or wear to the fuel pump gaskets and diaphram either. Do you think this could be coil related?

 

[Stoney54547]

Well I caved in and brought the 8hp Merc to the marina. Since this motor was used primarily as a supplemental "kicker" motor, the exhaust became restricted by carbon build-up. The only way to remove the residue is by removing the powerhead. Awesome design was my first thought.