Help to fit kill switch on twin 4hp Evinrude

Diamond_Geezur · 21 August 2020, 10:37

Hello all,

I'm fitting a kill switch to my Evinrude engine and it seems simple as it already has a 'stop' button so I figured it will be simple swap.

I have one issue/question however.

The new kill switch has a ground wire much like the current stop button. It also has one other wire which goes to the ignition. The stop button has TWO wires coming out and going into the ignition rather than one.

Is this a case of TWO wires for ignition as I have a twin cylinder engine, two spark plugs etc?

Do I just need to remove the stop button and fit kill switch by attaching the single kill switch ingnition wire to the TWO original ignition wires going into the ignition box/wiring loom.

I just wanted to make sure before I go cutting wires.

Thank you. I do have photos but hope my description will be enough.

HDAV · 22 August 2020, 10:20

How does current stop button work? Do you make to stop or break to stop? That the first thing to check then compare to the new kill switch, use a multi meter with continuity to test the operations.

Diamond_Geezur · 22 August 2020, 10:46

Many thanks for your reply - I currently have a little red button on the outboard which when held down it shuts the ignition off. I assume it may be the factory fitted one.

I'll have a play with the multimeter - was just confused about the three wires coming out of the stop button currently on outboard (make switch) rather than the two from the new to be fitted kill switch (break switch).

Oldman2 · 22 August 2020, 11:29

I thought the kill switch generally put the coils to ground (make switch) so replacing that with a break switch is back to front?

Diamond_Geezur · 22 August 2020, 11:44

Quote:

Originally Posted by Oldman2

I thought the kill switch generally put the coils to ground (make switch) so replacing that with a break switch is back to front?

Yes that does sound back to front.

I assumed it may be a simple swap but the first response suggested I have different switches.
https://www.amazon.co.uk/dp/B00LBPFL..._3vpqFbBVGV5A9
I have this kill switch which I am told is fairly easy to fit. As the RNLI and may sensible people would say, a kill cord on the outboard is essential.

My 1991 Evinrude two stroke twin 4hp outboard has a stop button on it, where the kill switch normally is. I imagine when the stop button is pressed this shorts the circuit and stops the ignition. I assume when the kill switch is activated the same happens.

My original question is just wondering how I fit the kill switch? I know it's down on engine such as these and many people fit kill switches with ease. It just seems to be overly complicated or I'm making it so.

It appears using the power of Google shows a sailing forum which has someone say they just swapped them.

"Active member
Our (now old) Johnson 3.3 came with just a push button to kill the engine. I sourced from an outboard repairer a kill switch and cord, removed the old switch (it only grounds out the ignition) and replaced it with the new kill cord one."

I'll get the electric meter out and make sure they do the same thing. I am still confused as to why my old switch has 3 wires coming out but new one has only two.

HDAV · 22 August 2020, 13:15

are all 3 connected on old switch if so to where? its possible its a NC/NO/C and the new one is just NO/C ie the stop switch can be wired as make or break switch the new one is a make only? Hence get testing with the meter......

Diamond_Geezur · 22 August 2020, 15:02

Quote:

Originally Posted by HDAV

are all 3 connected on old switch if so to where? its possible its a NC/NO/C and the new one is just NO/C ie the stop switch can be wired as make or break switch the new one is a make only? Hence get testing with the meter......

Engine diagram on here:
https://www.crowleymarine.com/johnso...arts/47767.cfm

The stop button has one wire going to earth/ground and the other two wires go from the stop button into the 'ignition module' - which then eventually feeds each of the two spark plugs. So to answer your question, all three wires are used on current stop button.

On new kill switch there is just two wires. One ground and one for ignition.

I wonder if this is because I have a two cylinder engine?

billows · 26 August 2020, 08:37

No expert but looks like there are two coils so shorting them together using your new switch probably not good. Most two cylinder engines have one coil and the spark plug fires in both cylinders at the same time but only the cylinder at compression ignites the fuel

Oldman2 · 26 August 2020, 11:14

Trace both the non earthed wires to be sure but I would hazard a guess that one is a feed to the coil thats being interrupted to link to the stop terminal then goes on as the 2nd wire to the coil. When you hit the kill switch you deck this coil feed as the switch is made to earth.