Carb Rebuild or Fuel Injection Cleaner?

[series2000]

Pick up an '85 Evinrude 40 (cheap) that sat two years but seems to run good. When I spray de-carb into the bottom carb it sputters and smokes like it's supposed to. But when I spray into the top carb the engine speeds up. It is definitely running on both cylinders. I doubt if this is normal. Should I do a carb rebuild or do you think running a strong mix of fuel injection cleaner or gumout in the fuel would get the job done?

 

[Walker]

Re: Carb Rebuild or Fuel Injection Cleaner?

Tear them down and clean them.

 

[angus63]

Re: Carb Rebuild or Fuel Injection Cleaner?

Top is probably running lean due to gummed up passages. Due a thorough rebuild on both carbs before the cylinders become the victims.