Kill switch doesnt kill engine

[ipbr21054]

Hi,
Just a quick question if i may.

As per titlle, petrol hedge trimmer starts & runs but when i operate the kill switch the engine continues to run,i then need to use the choke to kill the engine.

The switch is new & i have checked for continuity when the switch is made & broke.
The switch does as it should when operated so why does the engine contine to run & not kill the engine like it is supposed to ?

 

[Harry Bloomfield]

Check the wiring back to the ignition circuit, I believe these things work by shorting the magneto ignition to the body - so a break in the wire would prevent it killing the engine. Sanity check - if the switch closes to stop the engine, it is as I describe.

 

[lostinthelight]

I presume you have fitted the switch in place of the fuse?
if so test for continuity between switch end of earth wire to engine.
Then as sugested ,continuity of the wire from the coil. if you set meter to ohms and place one lead on switch wire and other to engine it should read whatever ohms of coil resistance is ,if it reads m ohms theres a break in the wire

 

[ipbr21054]

Yes fuse in bin and new switch fitted.
Switch does what it is upoosed to do as in post #1

Which ohm setting should i use ?

 

[lostinthelight]

what meter have you? If you havnt got auto range, set to ohms

 

[ipbr21054]

Hi,
I have now set to ohms and here are the results.

200 = 1
2000 = 1
20K = 1
200K = 1
2000K = 1
200M = 00.0 fluctuates to 00.2

This is the wire that comes out of the coil & through the engine casing connected to meter then the engine body.

 

[lostinthelight]

There's a break in the kill wire or you may have pulled it off the terminal when you were trying to separate the two halves before? That's if you have it hooked up as I think you have?

 

[Tigercubrider]

Is it an actual switch, or a button?

On older motorbikes you had to hold the kill button down until the engine stopped. Otherwise it would just falter but inertia made the motor restart instantly. Later, an off/on/off switch killed power to the ignition.

An old petrol lawn mower that I had shorted the spark plug by means of a piece of metal being pushed and held

 

[ipbr21054]

On / Off rocker switch just like what should be fitted.
Like the attached image but i didnt wire up the light as no need.

 

[Burnerman]

Use only the middle and one of the outer terminals......all its meant to do is to ground the kill wire.
John

 

[ipbr21054]

This switch has three terminals.
When you say middle & outer how do you know which is the light ?
There are two silver terminals & one gold terminal.
The two silver terminals are the break or make terminals.

If I take the wire from the engine body to one terminal then the multimeter from the other terminal to the engine body I hear the buzzer sound when the switch is made. When I break the switch the buzzer stops.

 

[Harry Bloomfield]

Leave the engine body out of it for now....

Connect your meter to the middle terminal of the switch, then to each outer terminal in turn, if there is no buzz, then throw the switch. It will buzz when both turned to on and across the correct two terminals.

Those two terminals then need connecting to the engine, one to the body, the other one to the kill wire.

 

[Burnerman]

The light won't work either way in this situation - there just isn't enough current.
Looking at the last paragraph there.......'When I break the switch the buzzer stops' That's the engine run position.
So, using the terminals you are using there will be just fine.
John

 

[ipbr21054]

I Understand the light will not work but I was just advising I have the two correct terminals connected.

 

[lostinthelight]

So its established that

I Understand the light will not work but I was just advising I have the two correct terminals connected.

So you need to establish that the switch to earth has continuity and so does the kill wire to coil...see post #3