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Not Starting, No spark
#1
J
jimvw57
J
jimvw57
So after some preventative maint this spring, First cut of the lawn. Just as we were finishing up, The motor died and wouldn't start. Checked gas, and it was mostly empty. Added a few gallons, and it won't start. I gave a shot of starter fluid, still no start. Pulled the sparkplug and it was drenched. Tried a new plug on the lead and... No spark.... Pulled the ground wire off the magneto and No spark. Removed the mag and cleaned off the pickup and flywheel magnet, No Spark. My guess is the Mag coil is bad, there are some teeth marks on the plug lead but it doesn't appear to be leaking. New one is on order, should be here in a few days. Good thing it was reasonably close to the shed. I got this so I wouldn't have to push a mower, thats not working too well.....
#2
S
slomo
S
slomo
Pull the oil dipstick and smell for fuel. You need air, fuel, spark at correct time and compression.
#3
J
jimvw57
J
jimvw57
so obviously (to me) I have no spark, even with the wire disconnected that grounds out the coil (shuts off the engine) When cranking over the engine, fuel/gas mixture will blow out the sparkplug opening so that would rule out compression and fuel, only thing left is no spark. Oil level is at full mark where it was when I changed oil before fall storage. Just before mower was shut off and won't start, 90% of the lawn was cut. Sounds like an electrical problem, maybe a coil overheating. Underside of shroud and cooling fins are clean. I'm going with a coil (magneto)
just bouncing off my theory on here to see if I am overlooking something. If I am out of line posting this, then feel free to delete the post and I will move on to where my posts don't offend anyone.
just bouncing off my theory on here to see if I am overlooking something. If I am out of line posting this, then feel free to delete the post and I will move on to where my posts don't offend anyone.
#4
Tiger Small Engine
Tiger Small Engine
If you have no spark with kill wire disconnected from ignition coil, then it is time for a new coil.so obviously (to me) I have no spark, even with the wire disconnected that grounds out the coil (shuts off the engine) When cranking over the engine, fuel/gas mixture will blow out the sparkplug opening so that would rule out compression and fuel, only thing left is no spark. Oil level is at full mark where it was when I changed oil before fall storage. Just before mower was shut off and won't start, 90% of the lawn was cut. Sounds like an electrical problem, maybe a coil overheating. Underside of shroud and cooling fins are clean. I'm going with a coil (magneto)
just bouncing off my theory on here to see if I am overlooking something. If I am out of line posting this, then feel free to delete the post and I will move on to where my posts don't offend anyone.
#5
S
slomo
Or if the coil mounting areas are rusted over it doesn't have a proper ground. I like to pull the coils and polish them up. Clean the mounting screws a bit.
S
slomo
Most of the time that is correct.If you have no spark with kill wire disconnected from ignition coil, then it is time for a new coil.
Or if the coil mounting areas are rusted over it doesn't have a proper ground. I like to pull the coils and polish them up. Clean the mounting screws a bit.
#6
S
slomo
S
slomo
Unless the coil is seriously rusted where it sits on the block. Meaning it would have a poor ground. Pull the coil. Clean and polish her and the mounting areas all up like new. Check for spark. No need to remove rust on the iron part of the flywheel.so obviously (to me) I have no spark, even with the wire disconnected that grounds out the coil (shuts off the engine)
If you see that much fuel blowing out, you have a flooding condition. That is why I mentioned pull the oil stick and smell for fuel. You declined to do that.When cranking over the engine, fuel/gas mixture will blow out the sparkplug opening so that would rule out compression and fuel
If it won't start, how could the coil be overheating?Sounds like an electrical problem, maybe a coil overheating
Like I said clean her up first before buying new untested parts.I'm going with a coil (magneto)
just bouncing off my theory on here to see if I am overlooking something.
Never happen here. Stick around and share with the group. Lot of great people on here.If I am out of line posting this, then feel free to delete the post and I will move on to where my posts don't offend anyone.
#7
J
jimvw57
J
jimvw57
So here is what fixed this. Replaced magneto and got spark instantly. machine started, then died. I suspected fuel so I drained the tank expecting to see some water in there, none found. I then realized there was too much gas through the carb, Pulled the carb and found the needle and seat was not shutting off the fuel flow, (something new) Carb is less than a year old, so we pulled it apart and blew air through needle and seat. now it was closing off with float. put it all together again and it was still flooding. Found the wires to the bottom of the float bowl weren't connected (oops) Changed the oil as it had gas in it, new plug, put everything back together and it started right up, no fuel leaks, good power, finished up the lawn and ran with no problems.
My guess is the carb started flooding from the needle and seat problem, made a weak mag give up, The gas gushing out was most likely from the wire I neglected to attach below the carb. I did try swapping back the old magneto and again, no spark (just because I was curious)
Hopefully this was the trouble with the mower for this year!!
My guess is the carb started flooding from the needle and seat problem, made a weak mag give up, The gas gushing out was most likely from the wire I neglected to attach below the carb. I did try swapping back the old magneto and again, no spark (just because I was curious)
Hopefully this was the trouble with the mower for this year!!
#8
D
dlgg7
D
dlgg7
FYI, usually that wire going to the bottom of the carb is a fuel-shutoff solenoid to stop gas from running into carb once key is turned off to stop backfires. Your float needle wasn't seating allowing fuel to overflow.
#9
J
jbisnette
Regular gas has alcohol in it and that will clabber up your carb because it draws moisture.
Always use premium gas no alcohol.
J
jbisnette
What kind of gas are you using?So here is what fixed this. Replaced magneto and got spark instantly. machine started, then died. I suspected fuel so I drained the tank expecting to see some water in there, none found. I then realized there was too much gas through the carb, Pulled the carb and found the needle and seat was not shutting off the fuel flow, (something new) Carb is less than a year old, so we pulled it apart and blew air through needle and seat. now it was closing off with float. put it all together again and it was still flooding. Found the wires to the bottom of the float bowl weren't connected (oops) Changed the oil as it had gas in it, new plug, put everything back together and it started right up, no fuel leaks, good power, finished up the lawn and ran with no problems.
My guess is the carb started flooding from the needle and seat problem, made a weak mag give up, The gas gushing out was most likely from the wire I neglected to attach below the carb. I did try swapping back the old magneto and again, no spark (just because I was curious)
Hopefully this was the trouble with the mower for this year!!
Regular gas has alcohol in it and that will clabber up your carb because it draws moisture.
Always use premium gas no alcohol.
#10
J
jimvw57
J
jimvw57
I always use non ethanol gas. at least that is what it is labeled on the pump, sometimes I wonder if someone made a mistake... also use the stations with seperate hoses for each grade of fuel.
#11
grumpyunk
If you have E10, 10% max ETOH, you can make it close to E0 by adding water, allowing it to precipitate, and then decanting the remaining fuel which will not have any alcohol mixed. It will be of lower octane, but 99% of the air-cooled OPE won't care as they run lower compression ratios and will not ping. The de-mixed fuel should store better.
tom
grumpyunk
If you want to know if your fuel is adulterated with ethanol, pour some into a glass jar. Add a glug of water, say 1/8c into a peanut butter jar half full. If there is ETOH in the 'premium' fuel, it will be drawn from the mixture and combine with the water. It should then fall to the bottom of the jar. The fuel will likely look cloudy.I always use non ethanol gas. at least that is what it is labeled on the pump, sometimes I wonder if someone made a mistake... also use the stations with seperate hoses for each grade of fuel.
If you have E10, 10% max ETOH, you can make it close to E0 by adding water, allowing it to precipitate, and then decanting the remaining fuel which will not have any alcohol mixed. It will be of lower octane, but 99% of the air-cooled OPE won't care as they run lower compression ratios and will not ping. The de-mixed fuel should store better.
tom
#12
F
farmerdave1954
F
farmerdave1954
Yeah, I always wondered how much gas a fuel pump hose held. If I take my 1-gallon container to a one-hose gas pump, select the ethanol-free gas, but the previous customer got the ethanol laced version, how much of the 1-gallon is going to actually be ethanol free? Likely not much. When getting a small amount like that, I always put a couple gallons in my truck before filling the 1-gallon jug for my weed eater. A recent remodel at the local gas station resulted in separate filler hoses for each grade, thank goodness. My truck probably wishes for the old one-hose pump to come back, though.
#13
Tiger Small Engine
2) Blame 10% ethanol on problems you are having. Lots of people do. I run 87 ethanol in every piece of equipment I have and don’t have problems. I also see lots of old fuel and fuel with water in it that the customers claim is “premium”. The never ending debate with 87 corn gas will never cease.
Tiger Small Engine
1) The carburetor solenoid is called the anti-afterfire solenoid, not fuel shut off solenoid.What kind of gas are you using?
Regular gas has alcohol in it and that will clabber up your carb because it draws moisture.
Always use premium gas no alcohol.
2) Blame 10% ethanol on problems you are having. Lots of people do. I run 87 ethanol in every piece of equipment I have and don’t have problems. I also see lots of old fuel and fuel with water in it that the customers claim is “premium”. The never ending debate with 87 corn gas will never cease.
#14
grumpyunk
grumpyunk
QUOTE: "The never ending debate with 87 corn gas will never cease."
Fuel that has ethanol added does have a more limited shelf life, or actually 'tank life' than plain gasoline. If left in the carburetor, exposed to atmosphere, it will tend to absorb water from the humidity in the air. It will also form what looks like a 'gel' if left in the float bowl for any length of time.
OTOH, if you use your equipment and do not let it sit with fuel that is deteriorating by absorbing water, it should run fine. In that respect, ethanol does make fuel more subject to going bad and leaving the carburetor unable to function properly.
In short, it just needs to be kept fresh more than fuel without ethanol added. I am not sure ETOH is a good fuel additive as there may be others that will have the same effect that do not cause susceptibility to absorbing water from the atmosphere.
tom
Fuel that has ethanol added does have a more limited shelf life, or actually 'tank life' than plain gasoline. If left in the carburetor, exposed to atmosphere, it will tend to absorb water from the humidity in the air. It will also form what looks like a 'gel' if left in the float bowl for any length of time.
OTOH, if you use your equipment and do not let it sit with fuel that is deteriorating by absorbing water, it should run fine. In that respect, ethanol does make fuel more subject to going bad and leaving the carburetor unable to function properly.
In short, it just needs to be kept fresh more than fuel without ethanol added. I am not sure ETOH is a good fuel additive as there may be others that will have the same effect that do not cause susceptibility to absorbing water from the atmosphere.
tom
#15
Tiger Small Engine
Tiger Small Engine
You are correct. Keep it fresh, keep it moving. Ethanol is hygroscopic (absorbs moisture). Just takes a little more thought is all, and you can save $.75 a gallon as well.QUOTE: "The never ending debate with 87 corn gas will never cease."
Fuel that has ethanol added does have a more limited shelf life, or actually 'tank life' than plain gasoline. If left in the carburetor, exposed to atmosphere, it will tend to absorb water from the humidity in the air. It will also form what looks like a 'gel' if left in the float bowl for any length of time.
OTOH, if you use your equipment and do not let it sit with fuel that is deteriorating by absorbing water, it should run fine. In that respect, ethanol does make fuel more subject to going bad and leaving the carburetor unable to function properly.
In short, it just needs to be kept fresh more than fuel without ethanol added. I am not sure ETOH is a good fuel additive as there may be others that will have the same effect that do not cause susceptibility to absorbing water from the atmosphere.
tom
#16
S
slomo
Look around at the pumps next time and several others. Notice most are not using 91 premium. Meaning it has more of a chance to go stale or water down compared to the more popular fuels. Use the most popular stuff you can get.
Typical push mowers and 0-turns, 87 octane is plenty. Chainsaws 91 octane or more is better. They have more compression.
Ask the sales person inside about how much 91 they buy compared to 87 octane.
S
slomo
Agree on the no alcohol.Always use premium gas no alcohol.
Look around at the pumps next time and several others. Notice most are not using 91 premium. Meaning it has more of a chance to go stale or water down compared to the more popular fuels. Use the most popular stuff you can get.
Typical push mowers and 0-turns, 87 octane is plenty. Chainsaws 91 octane or more is better. They have more compression.
Ask the sales person inside about how much 91 they buy compared to 87 octane.
#17
S
slomo
S
slomo
But, you have to fill up more often so you are not saving anything. E-10 has less thermal energy = less HP and torque. In a small engine, that could be big. I cut more grass with E-0 gas.and you can save $.75 a gallon as well.
#18
D
dlgg7
D
dlgg7
Oh well, to say it's NOT a fuel-shut off solenoid, it's EXACTLY what it does. Sorry making it simple!1) The carburetor solenoid is called the anti-afterfire solenoid, not fuel shut off solenoid.
2) Blame 10% ethanol on problems you are having. Lots of people do. I run 87 ethanol in every piece of equipment I have and don’t have problems. I also see lots of old fuel and fuel with water in it that the customers claim is “premium”. The never ending debate with 87 corn gas will never cease.
#19
ILENGINE
ILENGINE
Actually it is NOT. A fuel shutoff solenoid shuts off fuel flow into the carb. The afterfire solenoid doesn't effect fuel flow into the carb or the fuel bowl, and won't prevent the carb from overflowing if the float valve fails, only stops fuel from being drawn into the carb venturi to help prevent the bang after engine shutdown.Oh well, to say it's NOT a fuel-shut off solenoid, it's EXACTLY what it does. Sorry making it simple!
#21
A
Auto Doc's
A
Auto Doc's
Hi digg7,
I think both of you are correct. The solenoid is intended to physically shut the fuel off, and it prevents backfires and run-ons While the engine is still spinning once the key is shut off. It also takes a lot of the reliance away from the fuel float valve as well. As fuel evaporates from the carburetor over time, the float needle relaxes. This can actually create a flooding condition where fuel can find its way into the cylinders and eventually into the crankcase oil.
In addition, the solenoid acts as a redundant backup safety in the event to coil kill wire fails to ground the ignition coil(s) properly.
For most of my riders I have elected to install an inline fuel shutoff and remove or clip off the stop plunger of the solenoid. I got fed up with them always sticking and having to be cleaned. High heat and fuel do not play well together here in South TX. Along with that I don't mow my grass (weeds) but a few times a year because it does not grow all that fast. My riders mostly spend time pulling carts for my grandkids to ride in.
I think both of you are correct. The solenoid is intended to physically shut the fuel off, and it prevents backfires and run-ons While the engine is still spinning once the key is shut off. It also takes a lot of the reliance away from the fuel float valve as well. As fuel evaporates from the carburetor over time, the float needle relaxes. This can actually create a flooding condition where fuel can find its way into the cylinders and eventually into the crankcase oil.
In addition, the solenoid acts as a redundant backup safety in the event to coil kill wire fails to ground the ignition coil(s) properly.
For most of my riders I have elected to install an inline fuel shutoff and remove or clip off the stop plunger of the solenoid. I got fed up with them always sticking and having to be cleaned. High heat and fuel do not play well together here in South TX. Along with that I don't mow my grass (weeds) but a few times a year because it does not grow all that fast. My riders mostly spend time pulling carts for my grandkids to ride in.
#22
ILENGINE
The only purpose for the afterfire solenoid is to prevent the shutoff bang. It has no other effect on the carb, And in the case of Kohler engines the fuel afterfire solenoid only shuts off the high speed jet but the engine can still draw fuel through the idle circuit, which is the reason it is recommended that you shut off Kohler engines at full throttle.
ILENGINE
The afterfire solenoid has no effect on the float valve, or fuel flowing into the carb. So as the fuel in the bowl evaporates it will be replaced with fuel from the tank in a gravity flow situation. If the float valve fails the carb will still overflow and flood the engine,Hi digg7,
I think both of you are correct. The solenoid is intended to physically shut the fuel off, and it prevents backfires and run-ons While the engine is still spinning once the key is shut off. It also takes a lot of the reliance away from the fuel float valve as well. As fuel evaporates from the carburetor over time, the float needle relaxes. This can actually create a flooding condition where fuel can find its way into the cylinders and eventually into the crankcase oil.
In addition, the solenoid acts as a redundant backup safety in the event to coil kill wire fails to ground the ignition coil(s) properly.
The only purpose for the afterfire solenoid is to prevent the shutoff bang. It has no other effect on the carb, And in the case of Kohler engines the fuel afterfire solenoid only shuts off the high speed jet but the engine can still draw fuel through the idle circuit, which is the reason it is recommended that you shut off Kohler engines at full throttle.
#23
A
Auto Doc's
A
Auto Doc's
Unplug the solenoid while it is running at any speed, let me know what happens.The afterfire solenoid has no effect on the float valve, or fuel flowing into the carb. So as the fuel in the bowl evaporates it will be replaced with fuel from the tank in a gravity flow situation. If the float valve fails the carb will still overflow and flood the engine,
The only purpose for the afterfire solenoid is to prevent the shutoff bang. It has no other effect on the carb, And in the case of Kohler engines the fuel afterfire solenoid only shuts off the high speed jet but the engine can still draw fuel through the idle circuit, which is the reason it is recommended that you shut off Kohler engines at full throttle.
#24
ILENGINE
ILENGINE
On the Kohlers you can full choke cold start them with a failed fuel solenoid. I have seen it more than once in my career. I have even limped them into the shop. As soon as your open the choke they die, but will run roughly on full choke with the solenoid either not energized or stuck shut.Unplug the solenoid while it is running at any speed, let me know what happens.
#25
A
Auto Doc's
I don't disagree with you, and I have used that same process myself when a solenoid fails. It works sometimes and others not.
The other term used for these which is technically correct is "after fire solenoid". After fire occurs when fuel is drawn into the hot exhaust system and ignition spark has been shut off.
Most people use the term "backfire" because it is the most familiar term that has been around and taught for many years.
A
Auto Doc's
Hello ILENGINE:On the Kohlers you can full choke cold start them with a failed fuel solenoid. I have seen it more than once in my career. I have even limped them into the shop. As soon as your open the choke they die, but will run roughly on full choke with the solenoid either not energized or stuck shut.
I don't disagree with you, and I have used that same process myself when a solenoid fails. It works sometimes and others not.
The other term used for these which is technically correct is "after fire solenoid". After fire occurs when fuel is drawn into the hot exhaust system and ignition spark has been shut off.
Most people use the term "backfire" because it is the most familiar term that has been around and taught for many years.
#26
S
slomo
S
slomo
Put down you juicebox and take a breath guy. Getting all fired up on a mower forum is pretty silly.Thanks for being so argumentative. Whatever.