1975 15hp evinrude no spark

[floridaboater1]

Hi all i just picked up a 1975 evinrude 15hp electric start. I am getting no spark. Can someone please give me a wiring diagram. Also what wires do i check with my ohm meter for the stator and the timing base?

 

[floridaboater1]

Re: 1975 15hp evinrude no spark

please help how do i test my stator? points condenser?

 

[Willyclay]

Re: 1975 15hp evinrude no spark

Try the link below. Good luck!

Maintaining Johnson 9.9 Troubleshooting

 

[OptsyEagle]

Re: 1975 15hp evinrude no spark

Time to pop the flywheel and clean the points (or replace them). Most likely you have dirty points (especially if the motor sitting for a couple years). You can test them for continuity with a multimeter. Just connect the point lead to the meter and the other meter lead to ground and turn the flywheel cam until they close. If no continuity, they are dirty.

No real wiring diagram is needed. You have points that time the spark. They should be set to 0.020" gap. The voltage goes through the coils to the spark plugs. That's about it. I doubt it is your coils, since they rarely both fail at the same time, but when points corrode, they always seem to both corrode at the same time.

There are also two condensers in there, but they rarely fail.

 

[floridaboater1]

Re: 1975 15hp evinrude no spark

Time to pop the flywheel and clean the points (or replace them). Most likely you have dirty points (especially if the motor sitting for a couple years). You can test them for continuity with a multimeter. Just connect the point lead to the meter and the other meter lead to ground and turn the flywheel cam until they close. If no continuity, they are dirty.

No real wiring diagram is needed. You have points that time the spark. They should be set to 0.020" gap. The voltage goes through the coils to the spark plugs. That's about it. I doubt it is your coils, since they rarely both fail at the same time, but when points corrode, they always seem to both corrode at the same time.

There are also two condensers in there, but they rarely fail.

Thanks i pulled the flywheel and cleaned the points and readjusted them. Now i have spark but it will only run at high rpm. Im going to clean the carburetor and check compression. What should the compression be?

 

[Rick.]

Re: 1975 15hp evinrude no spark

The main thing is that they are within 10% of each other. Above 70 it should run, above 90 would be great IMO. You're doing well to clean the carb. next. I would run it for a few minutes before checking the compression. Just so you know the cylinders are lubed. Best of luck. Rick.

 

[OptsyEagle]

Re: 1975 15hp evinrude no spark

Yes. I would clean out the carb with a new rebuild kit. Also ensure that your carb is sync'd with your throttle cam. The roller on the carb should first touch the trottle cam at the exact point where the arrow on the cam is in the middle of the carb roller. The throttle cam can be adjusted by loosening the two small 5/16" nuts on the starboard side of that cam, under the flywheel and moving the throttle cam back and forth.

I have been argued with on this next one, but I find those motors have a tendency to foul the specified Champion spark plugs (UL81C) in fairly short time, so I find that NGK B7HS spark plugs, gapped at 0.030", will work a lot better. Others here, have noticed this phenomenon as well with the 1974 to 1976 9.9/15Hp series of motors. Good luck.

 

[kbait]

Re: 1975 15hp evinrude no spark

Agree w/Optsy^ on the NGK plugs for your motor. Also, when you have the flywheel off, check for lateral play in the armature plate. If it has any slop, that will translate directly to sloppy point gap, and lead to a bad scene.
Good luck!