1986 Johnson 40 bad fuel econ

[FLYonWALL]

Really only noticed this after I decarbed, changed the plugs and so forth. The carbs are clean I have taken them off and checked that out. Don't know if something is up with the choke or what. Anyway, I used to get about 70 to 80 miles per 12gal now I will be hard pressed to get 50. Where should I start? Also, the boat is having a tough go of it out of the hole on plane.

 

[Mark42]

Re: 1986 Johnson 40 bad fuel econ

Fist, inspect the new plugs. If wet and black, it is running rich. That will be wasting fuel, so check the carbs for floats being set wrong, correct jets, etc.<br /><br />Next, do a compression check. If one or both cylinders are low on compression, it will still run, but not as effeciently.<br /><br />If compression is up to specs, check ignition for misfiring. <br /><br />How are the ignition wires? Cracks and corroded ends inside the boot where you won't be able to see it easy can waste power too. Evinrude wire kits are cheap, and easy to install. Follow the direction exactly!!!!<br /><br />Someone who knows that year motor better will be along and post some more details, hopefully. <br /><br />Good luck!