Thread: Victa Coil and Carb wire

Originally Posted by Carter

Hey all,

was just reading the post on the kill switch for the victa mower engine. My case is the opposite as both wires that run into the carb are still connected AT THE CARB. But one is just loose at the other end (where ever that other end is haha). The wire that is contacted by the rotating cam in the carb when you move the throttle to STOP position is still connected at both ends (carb and coil), so it is the other wire that runs into the carb that isn't connected. Does any one know where this lone wire goes?

cheers

Josh

Hi, I am the one who posted the kill switch explaination/instructions. Have a couple of questions first up.
How have you established that the complete wire attaches to the coil? Visual tracing, meter, other? I ask because coil low tension (primary) winding is most likely in the range of 5 to 25 ohms resistance. If you try to check with a meter continuity (buzz) or similar it would activate anyway.
Is the motor an older double ended crank one as with the thread you refer to, or the later style canterlever crank model (Power Torque or later). Affects where the magneto is and access.

Basically, the coil has two windings and three connections. The low tension winding develops an induced current due to the flywheel magnets passing close by. One end connects to the ignition module or points/condensor, with a second lead connecting to the carby kill switch. The other end is earthed, and a second wire passes from the earth point to the kill switch.

The points or ignition module are normally closed allowing the coil LT current to flow. At an opportune time, the points are mechanically openned or the ignition module is magnetically triggered to break the circuit and arrest the LT current. This causes a very rapid collapse of the magnetic field in the coil core, resulting in a high voltage spike being generated in the coil high tension winding and transmitted to the plug. The two coil windings share a common ground point.

The kill switch (standard or modified) simply shorts out the points or ignition module so that it does not trigger a HT spark.

I see.

I probably left a bit out cause i originally posted this in the same place you did yours. There is the High tension lead off the coil which goes to the spark plug right? thats connected and know where that goes. There are two small connections on the coil as well as this, one seems to run straight back into the coil then down to the carby, and the other goes to the condenser. Both of these are connected at both ends. My predicament is there is another wire that comes out of the carby at the same place as where the first one from the coil goes in, that i have pulled out of somewhere and don't know where to put it. I have a feeling this is the earth wire? If it is do you know where a good place to earth it would be?

thank you for all your information to

Cheers

Josh

Josh, I have sketched the wiring for you as I recall it, but I haven't had a working Victa in the stable for maybe 20 years so I can't look and check it. Used to have a manual for them but think it went to recycling in the last cleanup as i couldn't find it for the previous discusion.

There are three possible configurations that would work.

The first one uses the black lines only and is at least a general drawing of the system.

The second one guesses that the double wire set at the kill switch is the coil 'trigger side. In this case ignore the black wires leaving the coil near the top and substitute the ryellowy green dashed ones. One runs from the coil trigger terminal to the kill switch, and the duplicate runs from there to the ignition module cable. I am fairly sure that this is not the configuration used as from memory the module can be changed without replacing the kill switch wiring, and teh module cable is cast into the module.

The second one guesses that double wire at the kill switch is the the earth cable. In this instance the cable runs from the coil earth terminal to the kill switch and branches back to the earth lug on the module where it is screwed/rivetted to the crankcase casting. This is shown by ignoring the lower black wires and substituting the blue dashed ones.

Does the motor run but not stop, or not run at all?

If it will run but not stop, then the loose wire is definitely the earth wire to the crankcase/module tab. In this case, you can crimp a lug onto it and earth it anywhere on the crankcase casting to restore the kill switch operation.

If it won't run, it could be that the loose end is from the coil trigger terminal (you say its connected) or the module (you called it capacitor but said it's connected), or it could be the coil earth terminal lead which you say is connected.

Hope this helps

Mal

Hi,

I have just signed up.

I have a problem. I disconnected the kill switch wires from the coil and the module. I measure the resistance on the coil and its shorted out. Though the kill switch would short to turn power off but its automatically shorted out in the coil and thats why I can not start.

Anyone selling a second hand coil?

Its the type with two jacks on it to connect to theplugs for ignition module and carby unit...

I am desperately after a second hand coil that works...

anyone?

Babaki,
The low tension winding is a very low resistance winding on a working coil, so it would be difficult to measure the resistance on a basic multimeter. It is quite likely that your coil is ok, and that the problem is somewhere else, possibly the ignition module or a worn cable shorting to ground. I have been around engines for 45 odd years and have a 1 owner 32yo car with 1.5million Km on it. About the only things that are original ex factory are the coil and the wheel nuts and studs. Pretty much the same with small engines, have thrown a fair few out as stuffed beyond economical repair, but never because of the coil failing.

Originally Posted by malb

Babaki,
The low tension winding is a very low resistance winding on a working coil, so it would be difficult to measure the resistance on a basic multimeter. It is quite likely that your coil is ok, and that the problem is somewhere else, possibly the ignition module or a worn cable shorting to ground. I have been around engines for 45 odd years and have a 1 owner 32yo car with 1.5million Km on it. About the only things that are original ex factory are the coil and the wheel nuts and studs. Pretty much the same with small engines, have thrown a fair few out as stuffed beyond economical repair, but never because of the coil failing.

woooow....thanks for that awesome information...so you reckon the coil is ok and it probably shows as short cause of the very low resistance...well if that is the ignition module then am I stuffed? is that hard to get? expensive?

or maybe I also have the coil checked but as you said it might go beyond economical so might not be worth it at all...

so can I test the ignition module by multimeter?

what measurements I should get as far as the resistance goes for coil and the module using a basic multimeter?

I measured the resistance using the buzzer which bips if continueos connection...I guess should have put it on ohm reading but because I was checking for shorts and I was not aware that they have very low resistance until I have been told by you and another champ, now it makes sense why the basic meter shows as short.

with cars, i never measured with meter after doing lots of mechanicall work and electrical cause when there was no ignition or the car shuts off I knew its the coil and replaced with a new one and it worked again...

lawnmowers pretty much the same scenario...well two times the coil failed on the EL falcon and the third time it was actually the module...

Low tension in a coil might be in the region of 2 to 3 ohms. The continuity buzzer on most modest multimeters will operate with resistances of 100 + ohms, it is basicly indicating a closed or open circuit for the item being tested.

To measure a coil properly you would need a 'bridge', an instument that compares a circuit with adjustable resistances, capacitances and inductances. You adjust the adjustable items in small steps until the unit indicates a match, then read the values of the adjustables from the dials on the unit.

Can't test the module by any means other than replacing it, pretty much as with cars, they either work or they don't.

Local mower repair shop should be able to supply an aftermarket universal module fairly cheaply, or a coil. Don't think there is a lot of aftermaket coils around, they are mostly genuine from what I have seen, because there are a lot of varieties and they are fairly reliable, so it's not an easy market to capture.

I see what you mean. that is the kind of test we did to measure resistance off a component in a circuit by paralleling it with an adjustable pot and measure untill it matches the measurement of that and be able to calculate it...

very smart....

i never thought of that at all....

measuring it normally shows 1 ohm...I disconnected the kill switch and still the magneto system could not fire up the coil, no spark i am suspicious at the coil...

they charge me $5 to test it.....it should be free

This is the coil i have:

http://s5.tinypic.com/2q0jz1w.jpg

Originally Posted by malb

Low tension in a coil might be in the region of 2 to 3 ohms. The continuity buzzer on most modest multimeters will operate with resistances of 100 + ohms, it is basicly indicating a closed or open circuit for the item being tested.

To measure a coil properly you would need a 'bridge', an instument that compares a circuit with adjustable resistances, capacitances and inductances. You adjust the adjustable items in small steps until the unit indicates a match, then read the values of the adjustables from the dials on the unit.

Can't test the module by any means other than replacing it, pretty much as with cars, they either work or they don't.

Local mower repair shop should be able to supply an aftermarket universal module fairly cheaply, or a coil. Don't think there is a lot of aftermaket coils around, they are mostly genuine from what I have seen, because there are a lot of varieties and they are fairly reliable, so it's not an easy market to capture.

Have you checked to see if the points are working? You should be able to measure the points opening and closing with a multimeter or buzzer. If you cannot see a short circuit when they are closed check their adjustment or clean with a points file .

Originally Posted by grahamjb

Have you checked to see if the points are working? You should be able to measure the points opening and closing with a multimeter or buzzer. If you cannot see a short circuit when they are closed check their adjustment or clean with a points file .

Hi Graham,

You may have missed some of the above info? But these particular victa's dont have points. They have a module that simulates the action of points.

And from what I have read here, can't be tested. Only a swap out to see if that is the problem.

I actually have 2 victas which have different problems and I might post that on a new thread.

Digger 12
Thanks for pointing out my error ....must be alzheimers. Time to crawl under a rock I think