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87 Johnson/Evinrude 50HP No Low End RPM's

G

greg_cmu

New member
Have a 2 cylinder 50 hp Johnson that was having some issues with dropping a cylinder and not able to get on plane. Since, have checked compression, both good at 145. Good Spark. Replaced both ignition coils, plugs and wires, power pack, timer and charge coil. Also, have taken apart the carbs and clean both. We are now running on both cylinders and able to get on plane running at close to our old speed. The problem is the low end, when we first hit the throttle it does not get up and go quite like it did before. We still do not have the power we used to on the low end. Not sure if it is a timing issue(since the flywheel was removed), or if it could be a fuel issue. If the butterflies in the carbs are opened up all the way, it runs great at WOT, but will not idle(constant backfire and missing to the point it just conks out). Please Help, would like to get back to rippin lips!!!
 
Unless the flywheel key is sheared, the engine is in time. Important that flywheel nut be torqued to 105 foot pounds, otherwise key will shear.

Spitting back at idle is normally caused by:

Butterflies opening before the scribe mark on cam is dead center with the throttle cam roller... OR... the fuel feed to the slow speed jets is restricted within the carburetors... OR... the idle jets are somewhat restricted (Clean manually with a piece of wire).
 
Thank you reeves, will take the carbs apart and do a thorough clean. Should I get a rebuild kit? Could the gaskets possibly be bad? Also, when i took the carb apart i noticed there are wear marks in one of the jet housing. Is that a sign of anything?
 
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