Testing a Universal control Module on a 2 stroke lawnmower with a digital multimeter

[fffd]

Hi,

I am trying to isolate the problem on the ignition on a 2 stroke power torque lawnmower engine. There is no spark at all. I tested the the coil around the magnet where the fly wheel is with the multimeter. It is giving me within range resistance 8.91Kohm on each terminal and the coil circuit is good. I checked the clearance between the magnets on the fly wheel and the coil using a business card and tried several times to adjust it a bit less and a bit more. It did not work. No Spark. I bought a new spark plug with no success. The only part remained to be tested is the ignition control module attached to the side of the engine . It is a squarish small piece with two terminals both attached to the coil and the ground , to a kill switch. How do you test it using a digital multimeter. The other part which I have not tested is the HT lead. How do you test it? It is hard connected to the coil. It is hard glued to the coil, But it is giving me an equal reading when I tested the coil terminals as I mentioned earlier.

I am puzzled about the" no ignition". The brand name of my 2 stroke power torque electronic ignition lawnmower is Victa. It is well known Australian household brand.

 

[bertsmobile1]

Hi,

I am trying to isolate the problem on the ignition on a 2 stroke power torque lawnmower engine. There is no spark at all. I tested the the coil around the magnet where the fly wheel is with the multimeter. It is giving me within range resistance 8.91Kohm on each terminal and the coil circuit is good. I checked the clearance between the magnets on the fly wheel and the coil using a business card and tried several times to adjust it a bit less and a bit more. It did not work. No Spark. I bought a new spark plug with no success. The only part remained to be tested is the ignition control module attached to the side of the engine . It is a squarish small piece with two terminals both attached to the coil and the ground , to a kill switch. How do you test it using a digital multimeter. The other part which I have not tested is the HT lead. How do you test it? It is hard connected to the coil. It is hard glued to the coil, But it is giving me an equal reading when I tested the coil terminals as I mentioned earlier.

I am puzzled about the" no ignition". The brand name of my 2 stroke power torque electronic ignition lawnmower is Victa. It is well known Australian household brand.

Short answer is you don't.
They get replaced with a known good one.
Most old style mower repair shops will flog you an old one for about $ 10.00 as they are one of the things you strip off an engine before you shot it in the Simms bin.
New ones are around $ 30.00.
Genuine Victa ones are better than the generic ones as most are designed to work with 4 stroke engines and have a much slower advance rate.
They will work but your mower will always seem a little sluggish.

 

[bertsmobile1]

As for the HT lead, you just test it for continuity.
If yours is getting too short you can dig it out and replace it .
The HT lead is screwed onto a threaded contact on the coil then encapsulated in resin.
So you can dig out all of the potting resin & replace the lead if you like.

 

[fffd]

As for the HT lead, you just test it for continuity.
If yours is getting too short you can dig it out and replace it .
The HT lead is screwed onto a threaded contact on the coil then encapsulated in resin.
So you can dig out all of the potting resin & replace the lead if you like.

Thank you for the info. I will look into it. I have a cut out HT lead from a whipper snipper. Would it be all right if I connect the coil lead to this one in order to elongate it and tape it with electrical adhesive tape?

 

[bertsmobile1]

Thank you for the info. I will look into it. I have a cut out HT lead from a whipper snipper. Would it be all right if I connect the coil lead to this one in order to elongate it and tape it with electrical adhesive tape?

Not a good idea.
Electrical tape will not take the heat and the glue is conductive at spark plug voltages.
The usual trick is to get a screw on champion spark plug cap.
They add about 1/2 to the length of the lead.
FWIW Victa coils rarely go bad it is usually the control module and in particular the control module retaining rivet gets loose & the module does not make a good earth contact with the crankcase.
Some times a bit of a clean up of the back of the module and the mounting hole with some steel wool + a new rivet will bring one back from the dead.
If you have some small jumpers make a good earth on the mower and a good earth to the module and spin the motor with no plug.
If the coil is good you generally can get a spark.
Whipper snipper plug leads are generally thinner but if that is your only option, solder the wires together, pull the ends close together then cover them with 2 or 3 pieces of glues heat shrink tube.
That will give you a relatively sound joint which will be water & spark tight.

The other trick that works well is an old screw on suppressor ( some times called a resistor ) it is a tube of bakalite about 30mm long with a screw at both ends Jacar electrics usually carry them.

I am assuming you have pulled the muffler & checked the bore for scoring and the rings ?

While you have it this far apart remember to replace both the O rings in the pull start and both the O rings on the manifold.

 

[fffd]

Not a good idea.
Electrical tape will not take the heat and the glue is conductive at spark plug voltages.
The usual trick is to get a screw on champion spark plug cap.
They add about 1/2 to the length of the lead.
FWIW Victa coils rarely go bad it is usually the control module and in particular the control module retaining rivet gets loose & the module does not make a good earth contact with the crankcase.
Some times a bit of a clean up of the back of the module and the mounting hole with some steel wool + a new rivet will bring one back from the dead.
If you have some small jumpers make a good earth on the mower and a good earth to the module and spin the motor with no plug.
If the coil is good you generally can get a spark.
Whipper snipper plug leads are generally thinner but if that is your only option, solder the wires together, pull the ends close together then cover them with 2 or 3 pieces of glues heat shrink tube.
That will give you a relatively sound joint which will be water & spark tight.

The other trick that works well is an old screw on suppressor ( some times called a resistor ) it is a tube of bakalite about 30mm long with a screw at both ends Jacar electrics usually carry them.

I am assuming you have pulled the muffler & checked the bore for scoring and the rings ?

While you have it this far apart remember to replace both the O rings in the pull start and both the O rings on the manifold.

Hi Birtmobile1,

I am trying to fix it step by step. I did take the muffler out and took also the combustion chamber side where the spark plug fits in. It was all dirty. I cleaned it thoroughly. I had a look at the O rings on the piston and the manifold. It looks good. My main issue is to get it sparking again. I already run a check with a multimeter on the module connectivity to the chasis, the grounding to the crank wall. It was good. I can take the pop rivet out and thoroughly clean the back of the module as well as the hole where the the pop rivet goes into. I did also another test to check the coil on its own, by over riding the ignition module, I did not get, not even, a tiny spark on the new spark plug. This is what I am worried about to.

With regards to the HT Lead extended it. I take note of what you advise me to do. Once I get it sparking I am going to do a general refurbishing of the whole lawnmower. I think I will go to Jaycar and buy some of these heat shrinking tubes. It is a good idea.

Thank you again. You are a champ.

 

[fffd]

Hi Birtmobile1,

I am trying to fix it step by step. I did take the muffler out and took also the combustion chamber side where the spark plug fits in. It was all dirty. I cleaned it thoroughly. I had a look at the O rings on the piston and the manifold. It looks good. My main issue is to get it sparking again. I already run a check with a multimeter on the module connectivity to the chasis, the grounding to the crank wall. It was good. I can take the pop rivet out and thoroughly clean the back of the module as well as the hole where the the pop rivet goes into. I did also another test to check the coil on its own, by over riding the ignition module, I did not get, not even, a tiny spark on the new spark plug. This is what I am worried about to.

With regards to the HT Lead extended it. I take note of what you advise me to do. Once I get it sparking I am going to do a general refurbishing of the whole lawnmower. I think I will go to Jaycar and buy some of these heat shrinking tubes. It is a good idea.

Thank you again. You are a champ.

Hi Birtmobile1,

Just to let you know, I have already dismantled the engine from the body of the lawn mower. That was the first thing I did. So what did you mean by having a good earthing of the mower? Do you mean connecting it to an earthing in my garden? In the normal circumstances, the whole lawn mower sits on four rubber wheels, there won't be a good earthing when it is running!!

 

[bertsmobile1]

No.
earthing is to the engine.

The way things work with the module is it makes & breaks the contact between the black wire which is at one end of the coil winding to earth which completes a circuit and allows a spark to be generated in a second set of wires that travels down the spark wire to complete its circuit by jumping the gap in the plug to again go to earth.
So you can think of the module as a fancy on - off switch which replaces the old points which again were just an on - off switch.
If you live near an old mower repair shop take your coil and module in and ask them to test them for you,
Wednesday is a good day to do it when they are likely to have the time.
The coil is repairable but you need a reasonable amout of skills to do it.
If the shop you pick is an old one , chances are they will have an old coil winding which they don't use any more & might sell it to you really cheap.

One thing I just thought off is to check your coil, there shaouls be a tab that the black wire goes on to and a second wire coming out that goes to a rivet or to a ring terminal that goes under the mounting bolt.
Ocassionally this wire breaks .

 

[fffd]

No.
earthing is to the engine.

The way things work with the module is it makes & breaks the contact between the black wire which is at one end of the coil winding to earth which completes a circuit and allows a spark to be generated in a second set of wires that travels down the spark wire to complete its circuit by jumping the gap in the plug to again go to earth.
So you can think of the module as a fancy on - off switch which replaces the old points which again were just an on - off switch.
If you live near an old mower repair shop take your coil and module in and ask them to test them for you,
Wednesday is a good day to do it when they are likely to have the time.
The coil is repairable but you need a reasonable amout of skills to do it.
If the shop you pick is an old one , chances are they will have an old coil winding which they don't use any more & might sell it to you really cheap.

One thing I just thought off is to check your coil, there shaouls be a tab that the black wire goes on to and a second wire coming out that goes to a rivet or to a ring terminal that goes under the mounting bolt.
Ocassionally this wire breaks .

Hi Birtsmobile1,

Thank you again for your prompt reply. I drilled the pop rivet out of the crank case and took the ignition control module out. I cleaned the area front and back where the pop rivet hole is. I also cleaned the back of the module. There is some type of resin or bakelite base there. I did a continuity test between the two terminals sometimes it is there and other times it is not there. Which means that the module, for all intended purposes, is doing its job. It cuts in and out. I tried to do a test with a 12 Volt battery tester light on a 8V DC supply . It worked also. I have no idea how the module would respond on a high voltage coming from the coil. There could be any where from 300-600V. Obviously it is not responding on my present coil, though the coil is showing correct readings on my multimeter. However the coil is not showing me any high voltage as such. Could it be boosted up by the ignition module as the voltage and current goes through it? That did not happen when I tested it with an 8V DC supply. I need a schematic diagram of my ignition coil module. It is IIDA EY850 JAPAN. I checked their website but could not get any more info on it. There is a newer model that does the same job.

I am a retired old timer. I am an Elecrtonic hobyist and also a jack of all trade but master of none. I got all sorts of tools in my workshop/garage. I rather fix things before I decide to replace them. Talking about the old rewinding tools for the coils, you are taking me back 65 years when I used to watch my Dad rewinding the old step up and step down transformers. He did his own rewinding tool. We used to coat the thin copper wire with Shalack to insulate it. He used to fix the old electrolytic capacitors, the old Mullard tubes and the variable resistor switches on the old radios.

I will be away the coming week. I would like to thank you, for now, for all your help. I will come get in touch with you at a later date. Bye for now

 

[bertsmobile1]

Hi Birtsmobile1,

Thank you again for your prompt reply. I drilled the pop rivet out of the crank case and took the ignition control module out. I cleaned the area front and back where the pop rivet hole is. I also cleaned the back of the module. There is some type of resin or bakelite base there. I did a continuity test between the two terminals sometimes it is there and other times it is not there. Which means that the module, for all intended purposes, is doing its job. It cuts in and out. I tried to do a test with a 12 Volt battery tester light on a 8V DC supply . It worked also. I have no idea how the module would respond on a high voltage coming from the coil. There could be any where from 300-600V. Obviously it is not responding on my present coil, though the coil is showing correct readings on my multimeter. However the coil is not showing me any high voltage as such. Could it be boosted up by the ignition module as the voltage and current goes through it? That did not happen when I tested it with an 8V DC supply. I need a schematic diagram of my ignition coil module. It is IIDA EY850 JAPAN. I checked their website but could not get any more info on it. There is a newer model that does the same job.

I am a retired old timer. I am an Elecrtonic hobyist and also a jack of all trade but master of none. I got all sorts of tools in my workshop/garage. I rather fix things before I decide to replace them. Talking about the old rewinding tools for the coils, you are taking me back 65 years when I used to watch my Dad rewinding the old step up and step down transformers. He did his own rewinding tool. We used to coat the thin copper wire with Shalack to insulate it. He used to fix the old electrolytic capacitors, the old Mullard tubes and the variable resistor switches on the old radios.

I will be away the coming week. I would like to thank you, for now, for all your help. I will come get in touch with you at a later date. Bye for now

Gees, keep that up I will be into the kitchen for some of mums lammingtons and a cup of warmed honey milk.

My old man did the opposite, dissolved the shelac off which got used to polish the side board with, remove all of the wire then ride is push bike all the way to Simms to sell the copper wire.
As for the ignition trigger,as said before you can not test it with a multimter.
It is a Hall effect trigger so detects the rising voltage in the coil and then trips this to earth when it gets to a predetermined value
It measures the rate of rise and time between peak power to delay the earthing thus controling the amount of advance.
It should not react to a flat voltage.

A rough as guts test for the coil is to energize it with a 9V transistor battery.
You should get a detectable spark ( only just ) by making & breking the circuit with the battery.
Rough as guts , but it usually is good enough.
Also check the magnets in the flywheel for strength. They should attract a screwdriver blade from about 1 ".
The module does nothing except open and close the circuit. They are just a solid state set of points, with a few balance resistors in order to change the timing a few degrees.
You should be old enough to remember the old ATOM Ignitions that came in about 7 different colours for different applications.
Well the Victa module is the old green one.
Victa paid Atom royalties in order to be the first to use the modules whinc they did for 30 years before the patient expired and every engine manufacturer put a royaltee free copy in their engines.
Shows just how chep some companies were.
Atom asked the princely sum of 50｢ royalties per unit which took the price up to 75｢ as they cost 25｢ to make