Boat

Johnson 50hp '82, running rough

J50BELCN, 7/2013

manifestation

after running fine on 2 outings, the day started out running fine. 15 minutes later, after I hit the throttle entering Pleasant bay from little Pleasant bay I hit a couple of bumpy waves. The engine started running at less than 1/2 speed, running rough. Same at idle: very rough, stalling, the idle lever made little difference in engine speed.

evidence that I should have given credence to

lower carburetor had a little gas dripping out the air intake.

tests

fuel bulb seemed to pump up fine. But it slowly got un-firm. Pumping it while underway made no difference

removing either plug wire caused stall

plugs looked OK. similar to each other

compression was good, same on both cylinders

stator coil and charge coil resistance within specs.

spraying starter fluid in upper carb caused engine to speed up, spraying into bottom carb had no effect.

holding plug wires close to block, spark had no trouble jumping 1/2"

solution

Lower float was banging into the roof of the bowl before that little pin had shut off fuel flow into the carb. Excess fuel dripping out the front of the carb and was making it run rough. Hitting those bumps must have bent the float.

the wild goose chase (or troubleshooting by credit card)

There was a crack in one of the coils, I replaced it. The voltmeter wasn't reading the right peak voltage output from the power pack (though you can't measure that with a voltmeter). Replaced it. thought maybe the fuel hose was collapsing inside. Replaced it. Swapped out the fuel pump with one I had, after pulling it from the head and finding no evidence of fuel leaking from vacuum hole. Replaced fuel lines in motor (They looked pretty crappy anyway). Anybody need parts?

not fuel pump,power pack,coils

remote control cables as shown , will sell by the individual cable piece ,if your looking for a hard to find cable or length i may have it , note the whole lot is not for sale , just individual cables at discount prices , will beat the big W prices , i like doing business , tel 617-202-8910 will discount email or leave tel # located at 247 pleasant st watertown

Biminis

60" tall bimini

6' or 8'

mechanics

max outboard 781 335 4456

performance mayhem 978 996 4573

Zeoli's Marine Services http://www.zeolimarine.com 7 Thayer Ave Revere, MA 02151-1604 (617) 846-2800

forums

http://www.marineengine.com/discus/messages/12478/287100.shtml http://www.johnsonoutboardforum.com/johnson-outboard-parts-forum/3710-johnson-50hp-82-running-rough.html mcktimo 6j http://forums.iboats.com/johnson-evinrude-outboards/johnson-50hp-82-running-rough-622339.html mcktimo 6j