1979 mariner/yamaha 25 hp problems

[Michael leblanc]

Ok went frogging last night got boat loaded up and we took off and could get on step it would really rev up its like it was struggling to go (had 4 people 3 of them 200 and over...lol and me 170) well I ran it like that for about 45 minutes wide open then it started missing so I pulled over to the bank and I took hood off and it idled perfect just no power when I take off so I pulled bottom plug wire off while it was idleing and it stayed running then I put that one back on and pulled top one off and it killed right away ..now just have a question would that be the little pack that went out that the plug wire runs in r would it be like a coil under the flywheel? any help would be helpful thank y'all

 

[Michael leblanc]

Sorry it couldn't get on step and wouldn't open up full throttle I would have it wot but it didn't sound like it

 

[oldman570]

The plug wire should go to the coil. The coil gets electricity from the switchbox to fire the plug. Test the coil and the switch box to be sure what is bad. There is no return on electrical parts, and they can be costly. JMO
Oldman570

 

[Michael leblanc]

Ok thank you I don't know how to check that can u explain how to check them and what to use