1981 70hp Mercury o/b no spark

[boaterinsd]

i have a spark on #1 and not 2 or 3 . I did have spark on 3 for a minute but it didnt stay. Are we talking switch box??? TIA

 

[Maxz695]

Re: 1981 70hp Mercury o/b no spark

most likely

 

[boaterinsd]

Re: 1981 70hp Mercury o/b no spark

does someone have a diagram for the thunderbolt 5 switchbox, wire colors and locations need to verify my 70 hp

 

[boaterinsd]

Re: 1981 70hp Mercury o/b no spark

ok, heres the results . I checked the stator its ok, i checked the rectifier- good. i checked all the trigger wires good. I only have cyl #1 sparking so i took each coil and attached it to the green wire terminal on the switch box, all have good spark on that terminal. So is the switch box bad , or do i need to switch around the 3 trigger wires to see if the dead cyl's follow in suit? Otherwise ill get a box for it. TIA

 

[boaterinsd]

Re: 1981 70hp Mercury o/b no spark

ok, i got the box installed. Started and ran ok, in the test tank at home for an hour or so. I took it to the lake and it didnt wanna start that easy. Then after we got to going it flet like we were dragging a huge tree . I went for a bit and things didnt change and we left. Now what?

 

[RaScLeS]

Re: 1981 70hp Mercury o/b no spark

check your spark if its running on all 3 move on, if its not keep fixing this ignition and trouble shoot the coils on the working cyl and make sure they are all good. once your sparking get the carbs cleaned out new fuel lines fuel pump make sure its clean and good. not much else to it. check my thread