Not Starting, No spark

jimvw57

Member
Joined
Aug 19, 2023
Threads
5
Messages
34
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.....
 

slomo

Lawn Pro
Joined
Jul 14, 2019
Threads
79
Messages
5,344
Pull the oil dipstick and smell for fuel. You need air, fuel, spark at correct time and compression.
 
Last edited:

jimvw57

Member
Joined
Aug 19, 2023
Threads
5
Messages
34
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.
 

Tiger Small Engine

Lawn Addict
Joined
Dec 7, 2022
Threads
3
Messages
1,342
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.
If you have no spark with kill wire disconnected from ignition coil, then it is time for a new coil.
 

slomo

Lawn Pro
Joined
Jul 14, 2019
Threads
79
Messages
5,344
If you have no spark with kill wire disconnected from ignition coil, then it is time for a new coil.
Most of the time that is correct.

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.
 

slomo

Lawn Pro
Joined
Jul 14, 2019
Threads
79
Messages
5,344
so obviously (to me) I have no spark, even with the wire disconnected that grounds out the coil (shuts off the engine)
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.
When cranking over the engine, fuel/gas mixture will blow out the sparkplug opening so that would rule out compression and fuel
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.
Sounds like an electrical problem, maybe a coil overheating
If it won't start, how could the coil be overheating?
I'm going with a coil (magneto)
just bouncing off my theory on here to see if I am overlooking something.
Like I said clean her up first before buying new untested parts.
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.
Never happen here. Stick around and share with the group. Lot of great people on here.
 

jimvw57

Member
Joined
Aug 19, 2023
Threads
5
Messages
34
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!!
 
Top