Johnson 40R72E I know nothing about boats!!

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hooter85742

Cadet
Joined
May 6, 2011
Messages
12
Ny Mom and I just bought a 14' Scorpin ski boat with a 40R72E Johnson on it. As far as the engine I know it is a 1972 40hp it has no wiring for a choke, no tilt motor, eletric or pull start. The shifter is a cable that does forward net and reverse. The other cable is the throttle. The carb was just rebuilt so they said, but they never started it. The wiring is all unhooked by the ign switchand a few wires are not hooked up at the engine. I messed around and did get it to fire and run for a few minutes. I put a 35 gal trash can filled with water, so I did not mess thing up by over heating it. Its not fun but It does not have the spot to put ears on it I think. I put two new a/c delco R45 plugs in it gapped at .30 like I found at Johnson's website. I think if I can get the wiring right everthing may be okay. I can not find the right wiring for this engine. I have a starter switch and a switch for the lights and nothing else. The harness has Red, White, Blue with a White strip, Blue, and Purple. I know red is hot, white is the start. If someone can help me out with some information about this engine and the wiring. And if I can hook a Volt meter and Tach up also. Thanks Hubert
 
ONERCBOATER

ONERCBOATER

Chief Petty Officer
Joined
Oct 11, 2010
Messages
536
Re: Johnson 40R72E I know nothing about boats!!

when you say it has no wiring for a choke are you saying it has no choke solenoid? I also and reading that it has either electric OR pull start correct?
anyhow the diagram that I am including i worked out off of my 1983 johny 15hp electric start.... pretty sure i can freely share it as it is my work. I know it is of a 1983 and a 15 instead of your 72 40hp... but thought it might help a bit while you wait for a better answer..... in the meantime when I get home from work I will look up your engine in the manual I have and see how much different it is...
 

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hooter85742

Cadet
Joined
May 6, 2011
Messages
12
Re: Johnson 40R72E I know nothing about boats!!

Well after messing with it more I found that I have one coil not firing. I pulled the top off and the point gap was off. I put it to .20 like the flywheel had printed on it. The Choke is manual, a black lever that you pull out the front of the case. It is pull start and electric start. Yes you picture looks very close to my wiring. Now I have to look up how to check the coil. The coil has three wires. Black-Ground, Blue/white-Hot, and the Spark plug wire. Thanks for the Pic It helps out alot.
 
H

hooter85742

Cadet
Joined
May 6, 2011
Messages
12
Re: Johnson 40R72E I know nothing about boats!!

I tok a few Picture and posted them on Myspace and Facebook. Myspace is
2880381
and Facebook is
2880381
I hope I did this right, LOL. After looking that the Picture that was sent I found I do not have as many parts and a few I do not know what they are. I do not have the ignition unit. I am not sure if I have anetral safty switch and a kill switch. also on the starter solerod it has four wires. Batt, Starter, Starting and two wires off the othe small pole a black wire going into the harness and a white wire going to nothing. The black wire is a ground.
 
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