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Murray 30" MER no spark
#1
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
I have taken pretty good care of this mower, sharpening the blade, replacing the air and fuel filters and spark plug and oil seasonally. A couple of years ago I did what I think in the automotive world is referred to as a frame off restoration, removing everything, cleaning and degreasing surfaces and replacing all the pins, bolts, washers etc. and belts with new. Over the years I've replaced other parts as required, batteries, safety switches, belts and ignition. This model has a Briggs & Stratton 28000 series 10HP single cylinder, L-head engine.
Recently upon attempting to start it, it cranked fine, started briefly, sputtered and that was it. All subsequent attempts to start it have failed. I've replaced the coil, ignition switch, bypassed all safety switches with paperclips but still there is no spark. You can literally hold the sparkplug wire in your hand while cranking. I've checked the diode with a meter and it reads differently forward and backwards and that's about all I know about that. So before blindly replacing all the safety switches I thought of seeking advice and here I am. Any suggestions are greatly appreciated. I haven't been able to mow in weeks and there are no kids who come around and offer.
Edit to add:
Murray model: 309029x92B
Briggs & Stratton model: 28R707, Type: 1120E1, Code: 030430ZD
Also replaced the wiring harness a couple of years ago.
Recently upon attempting to start it, it cranked fine, started briefly, sputtered and that was it. All subsequent attempts to start it have failed. I've replaced the coil, ignition switch, bypassed all safety switches with paperclips but still there is no spark. You can literally hold the sparkplug wire in your hand while cranking. I've checked the diode with a meter and it reads differently forward and backwards and that's about all I know about that. So before blindly replacing all the safety switches I thought of seeking advice and here I am. Any suggestions are greatly appreciated. I haven't been able to mow in weeks and there are no kids who come around and offer.
Edit to add:
Murray model: 309029x92B
Briggs & Stratton model: 28R707, Type: 1120E1, Code: 030430ZD
Also replaced the wiring harness a couple of years ago.
#2
Scrubcadet10
Scrubcadet10
should be a black kill wire that plugs to the ignition coil as well, pull it off and try to start. if you have spark with that pulled of the kill wire is being shorted to ground.
#3
H
hdsport
H
hdsport
From briggs forum.
The plug that runs to the carb bowl is the "Anti After fire valve" to prevent fuel from bring drawn into the cylinder after the key has been shutoff.
Most likely you have no spark because voltage got to the ignition coil and fried it, OR insulation was melted off the coil kill wire and it is now shorted to ground and causing the coil to not produce spark. Quick way to check is to unplug the kill wire from the coil and see if you've got spark. If you do with the wire unplugged the wire is shorted to ground or a key switch issue.
If you unplug the wire and still no spark , the coil is dead. BUT before you buy a new coil and put it on, you need to check to be sure there is no voltage on that kill wire. Any amount will fry the new coil.
The two sides that come from under neath the housing are most likely wires coming from the Stator (alternator).
More from forum.
Unplug the 1 wire that is going to the coil. Try to start. If it has spark with that wire unplugged. It is either shorted to ground or there is a problem with the key switch.
The plug that runs to the carb bowl is the "Anti After fire valve" to prevent fuel from bring drawn into the cylinder after the key has been shutoff.
Most likely you have no spark because voltage got to the ignition coil and fried it, OR insulation was melted off the coil kill wire and it is now shorted to ground and causing the coil to not produce spark. Quick way to check is to unplug the kill wire from the coil and see if you've got spark. If you do with the wire unplugged the wire is shorted to ground or a key switch issue.
If you unplug the wire and still no spark , the coil is dead. BUT before you buy a new coil and put it on, you need to check to be sure there is no voltage on that kill wire. Any amount will fry the new coil.
The two sides that come from under neath the housing are most likely wires coming from the Stator (alternator).
More from forum.
Unplug the 1 wire that is going to the coil. Try to start. If it has spark with that wire unplugged. It is either shorted to ground or there is a problem with the key switch.
#4
H
hdsport
H
hdsport
I had the same "no spark" issue and found that I crushed the black wire behind the starter when I did a starter pinion repair and then reinstalled the starter.
#5
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
Thanks, I'll try that but the black wire of which you speak is in plain sight and free of any kinks or pinches. I had to remove it and reattach it when I replaced the coil. But what the heck. Couldn't hurt. At this point I'd stand on one foot and sing Help me Rhonda.should be a black kill wire that plugs to the ignition coil as well, pull it off and try to start. if you have spark with that pulled of the kill wire is being shorted to ground.
#6
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
Thank you. I was unaware of a plug running to the carb bowl. I'll have a look. I replaced the key switch last week. Even though there is no visible damage to the black kill wire, unplugging it may lead to something else. Trial and error right?From briggs forum.
The plug that runs to the carb bowl is the "Anti After fire valve" to prevent fuel from bring drawn into the cylinder after the key has been shutoff.
Most likely you have no spark because voltage got to the ignition coil and fried it, OR insulation was melted off the coil kill wire and it is now shorted to ground and causing the coil to not produce spark. Quick way to check is to unplug the kill wire from the coil and see if you've got spark. If you do with the wire unplugged the wire is shorted to ground or a key switch issue.
If you unplug the wire and still no spark , the coil is dead. BUT before you buy a new coil and put it on, you need to check to be sure there is no voltage on that kill wire. Any amount will fry the new coil.
The two sides that come from under neath the housing are most likely wires coming from the Stator (alternator).
More from forum.
Unplug the 1 wire that is going to the coil. Try to start. If it has spark with that wire unplugged. It is either shorted to ground or there is a problem with the key switch.
#7
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
Disconnected the black kill wire but still no spark. With the blower housing removed the wire is in plain sight and completely free of any obstructions or crimps. Disconnected from the coil I'm able to pull it out with ease.should be a black kill wire that plugs to the ignition coil as well, pull it off and try to start. if you have spark with that pulled of the kill wire is being shorted to ground.
#8
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
I had a look and there is nothing connecting to the fuel bowl.Thank you. I was unaware of a plug running to the carb bowl. I'll have a look. I replaced the key switch last week. Even though there is no visible damage to the black kill wire, unplugging it may lead to something else. Trial and error right?
#9
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
Seems to have plenty of compression with good pressure at the spark plug hole. Guess I'll replace all safety switches again. Will take a few days as I'll have to order them since my truck is broke down as well.
#10
Scrubcadet10
Scrubcadet10
No spark with the wire unplugged is a bad ignition coil...
What did you set the air gap at?>
What did you set the air gap at?>
#12
Scrubcadet10
Scrubcadet10
Upside down coil would still spark. Just not at the right time
#13
B
bertsmobile1
It all depends upon why the timing chip is wired
Some will not work up side down because the energy pulse goes the wrong way.
0+0-0 or 0-0+0
B
bertsmobile1
not necessarily true.Upside down coil would still spark. Just not at the right time
It all depends upon why the timing chip is wired
Some will not work up side down because the energy pulse goes the wrong way.
0+0-0 or 0-0+0
#14
H
hdsport
Also, you can just bypass them and check for spark.
You have already replaced them once, so you could bench test the originals.
Keep us advised as you test your options.
H
hdsport
Safety switches are easy to test. You can bench test them for off/on continuity.Seems to have plenty of compression with good pressure at the spark plug hole. Guess I'll replace all safety switches again. Will take a few days as I'll have to order them since my truck is broke down as well.
Also, you can just bypass them and check for spark.
You have already replaced them once, so you could bench test the originals.
Keep us advised as you test your options.
#15
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
It's a new coil gapped with the included card. No spark with the previous coil either which is why I replaced it.No spark with the wire unplugged is a bad ignition coil...
What did you set the air gap at?>
#16
Scrubcadet10
Scrubcadet10
Do you have a multimeter? Check for voltage on the kill wire in the Off,On and Start key positions. Any voltage on that wire will fry a coil faster than a teenage burger flipper frying food.
A 12V test light will do as well.
A 12V test light will do as well.
#17
H
hdsport
H
hdsport
Ditto, MUST check this before anything else.Do you have a multimeter? Check for voltage on the kill wire in the Off,On and Start key positions. Any voltage on that wire will fry a coil faster than a teenage burger flipper frying food.
A 12V test light will do as well.
#18
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
Do you have a multimeter? Check for voltage on the kill wire in the Off,On and Start key positions. Any voltage on that wire will fry a coil faster than a teenage burger flipper frying food.
A 12V test light will do Kill wire isolated from coil
Kill wire isolated from coil shows 27V irrespective of key position.Do you have a multimeter? Check for voltage on the kill wire in the Off,On and Start key positions. Any voltage on that wire will fry a coil faster than a teenage burger flipper frying food.
A 12V test light will do as well.
#19
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
The only thing left in the circuit is the solenoid. All safety switches, key switch, and stator disconnected. 26.8V specifically with red meter wire to positive battery terminal and black meter wire to kill wire.
#20
B
bertsmobile1
B
bertsmobile1
I am not familiar with that particular mower but usually the kill wire is a ground wire as it grounds the coil so no spark is generated
As such it should be either open circuit to both sides of the battery with engine on and closed circuit to the negative side of the battery in the off position.
There should never be voltage on the wire.
And unless you have a funny battery you should never see voltages higher than 14V
Are you sure you are reading the meter correctly ?
Auto ranging meters could be reading kV , V or mV
As such it should be either open circuit to both sides of the battery with engine on and closed circuit to the negative side of the battery in the off position.
There should never be voltage on the wire.
And unless you have a funny battery you should never see voltages higher than 14V
Are you sure you are reading the meter correctly ?
Auto ranging meters could be reading kV , V or mV
#21
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
New meter, wrong setting. 12.5V to positive battery terminal, open to ground. The kill wire connects to the coil from the harness at the same junction as the stator. It's black in but yellow out the other side.I am not familiar with that particular mower but usually the kill wire is a ground wire as it grounds the coil so no spark is generated
As such it should be either open circuit to both sides of the battery with engine on and closed circuit to the negative side of the battery in the off position.
There should never be voltage on the wire.
And unless you have a funny battery you should never see voltages higher than 14V
Are you sure you are reading the meter correctly ?
Auto ranging meters could be reading kV , V or mV
Attachments
#22
Scrubcadet10
Scrubcadet10
i can't remember if i asked you or not, did you try flipping the coil over?
#24
Scrubcadet10
Scrubcadet10
some just say Cyl. SideIs there no printing on the coil that states this side out and such?
#25
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
Sorry for the delay, I've not been feeling well for a few days. I put the coil on the same as the old one came off and the one before it with the kill wire terminal on top. I should be feeling up to checking on it in a day or two. Until then, is there a way I can check the coil? Theoretically if I replaced the coil again and left the kill wire disconnected it would start and the problem would be stopping it? Considering what I've been through with this it seems like a better problem to have.
Thanks very much
Thanks very much
#26
Scrubcadet10
Scrubcadet10
Contrary to popular belief you really can't test a coil (Ohms) with a meter, the timing chip throws off all those readings..
A coil either,
1. Works
2. works with kill wire unplugged
3. works, but fails when hot (bad coil)
4. does not work with the kill wire plugged, but works with the kill wire unplugged. (kill circuit shorted to ground)
A coil either,
1. Works
2. works with kill wire unplugged
3. works, but fails when hot (bad coil)
4. does not work with the kill wire plugged, but works with the kill wire unplugged. (kill circuit shorted to ground)
#27
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
So I guess I'll be buying a new coil. Looking back there have been several issues with this mower over the years. Failing to shut off with the key, failing to start, and others. Once I was charged for wire harness replacement only to discover later that they had merely defeated the seat safety switch.Contrary to popular belief you really can't test a coil (Ohms) with a meter, the timing chip throws off all those readings..
A coil either,
1. Works
2. works with kill wire unplugged
3. works, but fails when hot (bad coil)
4. does not work with the kill wire plugged, but works with the kill wire unplugged. (kill circuit shorted to ground)
#28
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
Solved. After weeks of trying virtually everything, except of course, the right thing. At a whim I decided to look at some pics of coils online. Then I dug out the old one I had recently replaced. It was marked cylinder side and outside (or similar). I removed the recently installed coil to have a look. No visible markings other than the brand name. I reinstalled it using the marked orientation of the old coil, which was the reverse of how I removed it. It started right up.
The lesson here is never go by memory. Always check for indication of orientation and/or read the instructions. Measure twice, cut once. This has been one of my dumber moves and I'm embarrassed to admit it but if it saves someone else it will be worth it. I'll be 70 this fall. Maybe it's time for Prevagen.
Thanks to everyone who lent a hand on this. Time to go cut the grass.
The lesson here is never go by memory. Always check for indication of orientation and/or read the instructions. Measure twice, cut once. This has been one of my dumber moves and I'm embarrassed to admit it but if it saves someone else it will be worth it. I'll be 70 this fall. Maybe it's time for Prevagen.
Thanks to everyone who lent a hand on this. Time to go cut the grass.
#29
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
Well it seems I celebrated too early. I got the front yard mowed. Started on the back and noticed grass was no longer coming from the discharge chute. So I stopped, turned off the key to clear the clog. Following that when I turned the key I got nothing. I pushed it back up into the shed and put the battery charger on it despite being relatively certain that was not the problem. After an hour it's still dead, not a peep when the key is turned. Being thorough I checked all the switches with the meter and all checked good. I swapped the key switch with the one I recently removed. Still nothing. With the key turned crossing the solenoid with a screwdriver turns the starter but no spark. I removed the blower housing, disconnected the kill wire, replaced the cover, turned the key and still nothing. But with the key in the on position and crossing the solenoid with a screwdriver it started. I didn't think to see if it would start with the key in the off position. Of course I had to kill it with a screwdriver shorting the sparkplug to ground. Fortunately it began to rain because I was just about to set it on fire.
#30
H
hdsport
Please advise.
Thanks.
H
hdsport
I guess we're all wondering where you ended up with this effort.Well it seems I celebrated too early. I got the front yard mowed. Started on the back and noticed grass was no longer coming from the discharge chute. So I stopped, turned off the key to clear the clog. Following that when I turned the key I got nothing. I pushed it back up into the shed and put the battery charger on it despite being relatively certain that was not the problem. After an hour it's still dead, not a peep when the key is turned. Being thorough I checked all the switches with the meter and all checked good. I swapped the key switch with the one I recently removed. Still nothing. With the key turned crossing the solenoid with a screwdriver turns the starter but no spark. I removed the blower housing, disconnected the kill wire, replaced the cover, turned the key and still nothing. But with the key in the on position and crossing the solenoid with a screwdriver it started. I didn't think to see if it would start with the key in the off position. Of course I had to kill it with a screwdriver shorting the sparkplug to ground. Fortunately it began to rain because I was just about to set it on fire.
Please advise.
Thanks.
#31
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
Fortunately the mower is running. Unfortunately, I'm currently mowing without any safety features. The mower will start only by disconnecting the kill wire and crossing the solenoid with a screwdriver. The key is irrelevant. Of course this route disables all safety features. I use the same screwdriver to short the spark plug to ground to kill the engine. Not ideal but it works. As long as I don't fall off of the mower. My best guess is the wire harness may be shorted somewhere. I ordered two momentary push switches, one to start and one to kill but haven't done anything with them yet.
#32
Scrubcadet10
Scrubcadet10
Are your blades disengaged?
#33
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
Yes. I always make sure to disengage the blade before killing the engine. Because of course, in normal circumstances, it wouldn't start. Another disabled safety feature to worry about. I have the exhaust chute covered with a mulch cover but still, not advisable.
#34
B
bertsmobile1
B
bertsmobile1
It never fails to amaze me what people will do to mower wiring rather to work out which part has failed .
#35
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
If you have any helpful suggestions I would be grateful to hear them because I have tried literally everything I can think of. I didn't just begin by jacking the wiring.It never fails to amaze me what people will do to mower wiring rather to work out which part has failed .
#36
B
bertsmobile1
B
bertsmobile1
You make some bypass jumper leads that have a male terminal at each end
Get a globe and hook some wires to it
Connect one end to a power source and the other to the magneto kill wire
The kill wire is normally open circuit then goes to ground to stop the engine
SO if the kill circuit has a short some where, the globe will light
Now one at a time bypass each switch to the running condition and watch the light
The switch you bypass that causes the light to go out is the faulty one or the wiring between the switch & the previous one is shorting to the frame.
Works best if you get a circuit diagram and work backwards from the magneto to the key switch.
Safety switches should always be back tested at the plug because silly things like the switch shifting a little can mean while the switch itself is working the mower does not move the plunger far enough to activate it
I regularly put a self tapper into the end of plungers to compensate for wear not depressing the plunger far enough to work.
Get a globe and hook some wires to it
Connect one end to a power source and the other to the magneto kill wire
The kill wire is normally open circuit then goes to ground to stop the engine
SO if the kill circuit has a short some where, the globe will light
Now one at a time bypass each switch to the running condition and watch the light
The switch you bypass that causes the light to go out is the faulty one or the wiring between the switch & the previous one is shorting to the frame.
Works best if you get a circuit diagram and work backwards from the magneto to the key switch.
Safety switches should always be back tested at the plug because silly things like the switch shifting a little can mean while the switch itself is working the mower does not move the plunger far enough to activate it
I regularly put a self tapper into the end of plungers to compensate for wear not depressing the plunger far enough to work.
#37
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
Sorry but, globe?You make some bypass jumper leads that have a male terminal at each end
Get a globe and hook some wires to it
Connect one end to a power source and the other to the magneto kill wire
The kill wire is normally open circuit then goes to ground to stop the engine
SO if the kill circuit has a short some where, the globe will light
Now one at a time bypass each switch to the running condition and watch the light
The switch you bypass that causes the light to go out is the faulty one or the wiring between the switch & the previous one is shorting to the frame.
Works best if you get a circuit diagram and work backwards from the magneto to the key switch.
Safety switches should always be back tested at the plug because silly things like the switch shifting a little can mean while the switch itself is working the mower does not move the plunger far enough to activate it
I regularly put a self tapper into the end of plungers to compensate for wear not depressing the plunger far enough to work.
#39
S
slomo
Just wait till the screwdriver gets welded to the starter and burns the mower and his house to the ground.
S
slomo
Spend more time and energy "rigging" it up than repairing it. LOLIt never fails to amaze me what people will do to mower wiring rather to work out which part has failed .
Just wait till the screwdriver gets welded to the starter and burns the mower and his house to the ground.
#40
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
I have no old headlamps lying around and cannot think of any other 12V type light device to use. My vehicle has been broke down in my driveway for the past couple of months and nowhere within walking distance. I also have a water leak under my house requiring me to turn on the water only as needed. It's been a difficult summer and I've had to pick my battles. If anyone has any suggestions of something suitable for the purpose I could order from Amazon I would be able to do that.
#41
L
L0n3s0m3_M0w3r
L
L0n3s0m3_M0w3r
Searching frantically I managed to find a 12V blue fluorescent tube I bought years ago to go inside a PC case. I connected it up as suggested and it lit up. It remained lit while one by one, I bypassed all three switches with a jumper, never going out until disconnected.
#42
B
bertsmobile1
B
bertsmobile1
I gave instructions about what to do back in post # 36
This requires you to have a set of booster cables that most home owners have in the boot of their cars and a couple of pieces of wire
If you really want my assistance do what was asked & post results
If you can not be bothered to do what I have requested then I can not be bothered with your problems
Your choice
This requires you to have a set of booster cables that most home owners have in the boot of their cars and a couple of pieces of wire
If you really want my assistance do what was asked & post results
If you can not be bothered to do what I have requested then I can not be bothered with your problems
Your choice
#43
L
L0n3s0m3_M0w3r
"You make some bypass jumper leads that have a male terminal at each end
Get a globe and hook some wires to it
Connect one end to a power source and the other to the magneto kill wire
The kill wire is normally open circuit then goes to ground to stop the engine
SO if the kill circuit has a short some where, the globe will light
Now one at a time bypass each switch to the running condition and watch the light"
With alligator clips I connected one side of the light to the + battery terminal of the mower and the other side to the kill wire. The light lit up. I independently bypassed each switch with a jumper and the light never went out.
What I did was follow your instructions as I understood them. From my point of view your latest post differs significantly from post #36 so it's possible I misunderstood. The key position was not specified so I did the test both ways. If what I have done is not what you meant please clarify.
There have been several suggestions prior to your contribution and I have tried every one.
I appreciate everyone's time and effort.
Thank you
L
L0n3s0m3_M0w3r
Either I didn't make myself clear or I didn't understand your suggestion.I gave instructions about what to do back in post # 36
This requires you to have a set of booster cables that most home owners have in the boot of their cars and a couple of pieces of wire
If you really want my assistance do what was asked & post results
If you can not be bothered to do what I have requested then I can not be bothered with your problems
Your choice
"You make some bypass jumper leads that have a male terminal at each end
Get a globe and hook some wires to it
Connect one end to a power source and the other to the magneto kill wire
The kill wire is normally open circuit then goes to ground to stop the engine
SO if the kill circuit has a short some where, the globe will light
Now one at a time bypass each switch to the running condition and watch the light"
With alligator clips I connected one side of the light to the + battery terminal of the mower and the other side to the kill wire. The light lit up. I independently bypassed each switch with a jumper and the light never went out.
What I did was follow your instructions as I understood them. From my point of view your latest post differs significantly from post #36 so it's possible I misunderstood. The key position was not specified so I did the test both ways. If what I have done is not what you meant please clarify.
There have been several suggestions prior to your contribution and I have tried every one.
I appreciate everyone's time and effort.
Thank you
#44
B
bertsmobile1
B
bertsmobile1
The kill wire is either open ( not connected to anything ) to run , or ground to stop the engine
If the globe is illuminated when connected between the kill wire & the battery + anytime other than when the key is off then one of the safety switches or the wires between them is faulty.
Apart from the cranking circuit, all of the safety switchers are GROUND switches, they make a ground contact with the kill wire .
I hope this clarrifies things a bit for you.
The cranking circuit is the only powered safety circuit ( except if relays are being used ) .
The cranking circuit goes from the S terminal on the key switch through the PTO switch, through the parking brake switch , through the neutral switch ( if fitted ) then to the trigger terminal on the solenoid .
If the globe is illuminated when connected between the kill wire & the battery + anytime other than when the key is off then one of the safety switches or the wires between them is faulty.
Apart from the cranking circuit, all of the safety switchers are GROUND switches, they make a ground contact with the kill wire .
I hope this clarrifies things a bit for you.
The cranking circuit is the only powered safety circuit ( except if relays are being used ) .
The cranking circuit goes from the S terminal on the key switch through the PTO switch, through the parking brake switch , through the neutral switch ( if fitted ) then to the trigger terminal on the solenoid .