1963 Evinrude 40hp 40352

tcross

Recruit
Joined
Jun 7, 2014
Messages
4
Just bought 15' runabout with the 40hp Evinrude. First time on water everything fine then started loosing rpms at WOT. Idle, slow - med speed OK. Checked plugs (NGK) - wet with slight carboning. On my small 6hp Johnson, had similar problem and found replacing the fuel connections and fuel pump solved problem. Figuring something similar and would like some advice.

What components should I test/repair first? Carb filter? Fuel pump?

I trace fuel lines coming into the
 

kodibass

Master Chief Petty Officer
Joined
Apr 10, 2010
Messages
864
First thing I would do is get rid of the NGK plugs, and put champions in, when you loose the rpms is the primer bulb firm? have you tried adjusting the high jet for rich/ lean, also might be dropping fire in one plug. if bulb is not firm when it happens try squeezing it and see if it improves. air vent on tank?
 

BonairII

Commander
Joined
Jun 7, 2011
Messages
2,727
Wet plugs means no fire. Get the correct plugs...then check the QUALITY of spark(not just IF it's getting spark). probably dropping a cylinder when the coil(s) get warm.
 

tcross

Recruit
Joined
Jun 7, 2014
Messages
4
Progress?

Well I replaced the entire ignition (coils, points, cond, plugs) and had good WOT until one of the screws holding the one of the coils worked loose (my bad for not double checking everything). Screw came up loose and rubbed against the flywheel spraying metal shavings throughout. Limped home on one cylinder. Pulled flywheel, cleaned and replaced screws with stainless equivalents. Tested spark - 1/2 - 7/16" easy.

In the water, still only 1 cylinder - damn, didn't use new plugs. This having to launch everytime I want to test or tune this motor is a PITA. Anyone know if is there a test prop for this beast? Or does anyone have a McGiver solution for tuning this motor at home?

Thanks
 
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