Ignition switch Johnson 70 hp -79

[tgronberg]

I just bought used Johns?n 70 hp -79 and I am replacing the ignition switch. I would kindly ask help with the wiring diagram. In my new switch there are A, M, B, M, I and S in the back. Also there is place for screw in between B and M. I have two Clymer manuals but those don?t include my new -79 70hp engine. I have chematics from Clymer for smaller engine and I am just wondering whether that diagram would work in my case? There was incorrect ignition switch installed which did not work when I bought the motor and that?s why I can?t just go one wire at the time method... Thank`s ahead!

 

[Joe Reeves]

Re: Ignition switch Johnson 70 hp -79

What are the colors of the wires that will attach to the ignition switch?

 

[tgronberg]

Re: Ignition switch Johnson 70 hp -79

I will go tomorrow to check out the colors of all the wires and I will get back to you after that if you don`t mind. I feel pretty stupid since I had my mobile phone with camera with me the other day when I opened it up but did not realize to take the photo. I suppose I was just too anxious after succesful change of motor. I had Johnson 65 hp -73 previously in my boat (original paggage) and I feel that now I got the perfect motor for my boat 4,7 meter Raisport. Anyway I will write more info tomorrow. Thank you!

 

[tgronberg]

Re: Ignition switch Johnson 70 hp -79

I have wires connecting to ignition switch as follows:

1 Purple
2 Purple/white
3 Red
4 Black/yellow
5 Black
6 Yellow/red
7 Grey
8 Brown

My new push in-choke ignition switch is SEAWOLD 20120 and it`s got instructions for connection as follows:

B-battery
M-magneto circuit (not regular wire connection but place for small screw)
C-choke
I-ignition circuit
S-solenoid
A-accessory circuit
M-(no info)

I would be very grateful if I would get help with this.

 

[jtexas]

Re: Ignition switch Johnson 70 hp -79

Purple (switched accessory 12V) = A
Purple/white (choke) = C
Red (battery 12V) = B
Black/yellow (kill circuit) = M
Black (engine block ground) = other M
Yellow/red (start) = S
Grey = tachometer sender - goes to the accessory socket in the control box or else directly to SND terminal on tach

 

[Joe Reeves]

Re: Ignition switch Johnson 70 hp -79

Yep, what Tex said.

I'd add that the Black/Yellow goes to the raised boss type "M" terminal if one exists on that switch. The OMC switch has one raised "M" and one regular "M" terminal.

 

[tgronberg]

Re: Ignition switch Johnson 70 hp -79

Hello everybody,
I eventually had chance to go to my boat today and installed the new ignition switch according to fine advices by You. It was a piece of cake to do now and it works as it`s supposed do. Thank you very much.
Then I launched the boat to the sea. It started and idled beutifully. When I put forward gear on and throttled engine died. I checked the fuel flow and spark but I still belive that it`s the carburators. I will clean these in the near future but I would like to ask Your opinion about installing temporarily perfectly functioning carburators from my old Johnson 65hp -73. I already took them out and I thought that I`ll go tomorrow to put them on and find out if it`s carb problem. What do you guys think? Am I going wrong the big way...?
Thanks again!

 

[iwombat]

Re: Ignition switch Johnson 70 hp -79

Check the part numbers. If the assembly is the same, sure. If not I woudn't try it w/o knowing all the jetting matches up.

Why do the swap anyway? Once you've got the carbs off, you're most of the way to a carb rebuild already. Why bother doing the swap all over again once the rebuild is done?

 

[jtexas]

Re: Ignition switch Johnson 70 hp -79

Why do the swap anyway? Once you've got the carbs off, you're most of the way to a carb rebuild already. Why bother doing the swap all over again once the rebuild is done?

just what I was thinking - I guess maybe if you just can't wait on the parts..............if the throttle cams aren't the same shape or aren't positioned the same it won't work right.

 

[tgronberg]

Re: Ignition switch Johnson 70 hp -79

Ok. Now I have taken the carbs apart cleaned those and put them together. I also put in all new fuel lines and fuel tank. Now it once again idles fine and starts ok but it won`t run right. It stalls if I throttle to quickly but with slow building up towards WOT I can make the boat plane and go about 25 knots. I now suspect that I have problem with the carb adjustment. Motor is not getting enough air. Furthermore I simply can`t figure out how to adjust he carbs since I seem to have slow speed jets underneath a screw on the top of the carbs. No springs or any kind of adjustment screw. Would I kindly get help with this issue please. I am sure there must be some way of adjusting the mixture. I feel that is the thing to accomplish in order to get motor running fine. Thanks ahead!

 

[Joe Reeves]

Re: Ignition switch Johnson 70 hp -79

There are no carburetor adjustments pertaining to the fuel/air mixture. Those brass jets simply screw down until they bottom out and seat. The cover screw for the top idle slow speed jet should have a red washer in back of it, and it should be tightly seated.

Did you acyually remove and manually clean those jets, especially the fixed brass high speed jet that's located in the bottom center portion of the float chamber..... in back of that screw at the bottom front area of the float chamber? If not, do so as a clogged jet will result in exactly the problem you're encountering.

Another thing..... that cam that glides into the carburetor throttle cam roller, there's a scribe mark on the cam. The throttle butterflies must just start to open when that scribe mark is dead centered with the roller, not before or after.

(Carburetor Float Setting)
(J. Reeves)

With the carburetor body held upside down, the float being viewed from the side, adjust the float so that the free end of the float (the end opposite the hinge pin) is ever so slightly higher (just ever so slightly off level) than the other end. And when viewed from the end, make sure it is not cocked.

http://stores.ebay.com/Evinrude-Johnson-Outboard-Parts-etc?refid=store

 

[tgronberg]

Re: Ignition switch Johnson 70 hp -79

Thanks for your advice. I did clean all the jets in three carbs and thoroughly also everything in the carb bodies. I feel that everything is in order carbwise since you told me that there`s no air/fuel adjustment possibility.

I started thinking about that carb throttle cam roller thing you mentioned and I think my cam follower is not centered correctly in between those two lines marked in roller cam and that might be the reason why the motor runs fine except I get the feeling that it is running under the blanket!!! ( roller is maybe 2-3 mm below the center position) If I understand correctly my carbs would not therefore be in sync with the advanced ignition perfectly. Am I correct? Is there anything special to concider adjusting the cam follower?

I worder if I`am on the right track...

 

[Joe Reeves]

Re: Ignition switch Johnson 70 hp -79

 

[tgronberg]

Re: Ignition switch Johnson 70 hp -79

Than you very much for the diagram/photo, I will go to the boat tomorrow morning and try adjustment out.
I`ll let you know how it went..
Thanks!

 

[tgronberg]

Re: Ignition switch Johnson 70 hp -79

I adjusted the Cam follower by one turn in order to get it exactly centered with the mark. I also put in new fuel pump. Motor started to run nicely and eventually I figured the main reason motor not running with so many RPM under load. I realized that my new engine had 21" propeller. I immediately put my older 15" propeller and went for the test drive. What a change!!!! Engine was running perfectly with high RPM. My boat took off to plane immediately and motor was running like a dream. So now I can gladly inform you all that new motor has now been succesfully installed and everything is working fine.

I would like to thank all of you for out standing attitude of helping out. Thank you very much guys and now I can spend rest of the summer with happy boating !!!