75 hp Stinger Johnson outboard

[ch]

I just acquired this motor on a 1973 crestliner bowrider 16ft boat. It starts right up and runs but doesn't have much power.
One of the coils has a crack in it which may be causing this problem? Is there a way I can tell for sure? Is changing the coil a DIY project.

 

[Bosunsmate]

Re: 75 hp Stinger Johnson outboard

Yes DIY easy.
Pull the spark plug boot off and ground the sparkplug somewhere it wont light the fuel coming from the motor. Check it sparks.
Do that for all cylinders.
Also run at night and seee if you see any sparking with sparkplugs back in motor, the motor should stay dark.
Coil problems often happen when they heat up so warm the motor up first if you can

 

[Bosunsmate]

Re: 75 hp Stinger Johnson outboard

Running at night is to check no electricity is escaping out of the coils and other electric lines.
To be very confidence with spark performance check it jumps a 7/16 gap consistently.

 

[ch]

Re: 75 hp Stinger Johnson outboard

Thanks for the help. I changed the plugs and it runs much better, but it still takes it a while to get up to speed. Should this setup be quick enough to get a skier up? The coil with the crack should probably be replaced, what should I get for a coil

 

[Bosunsmate]

Re: 75 hp Stinger Johnson outboard

Yep the 75 should get a skier up ok so long as not too many people on board.
You should check compression too if you have further concerns about the power.
http://forums.iboats.com/johnson-evinrude-outboards/compression-test-jb-313963.html

Coils probably around $45.