John Deere L110 No Spark.

[Lou the mower killer]

I have a John Deere L110 ( Kohler 17.5 ) that quit running. I was mowing and on my last strip the engine slowed down to where it was running at about half the speed of it's slowest throttle setting. I stopped where i was and just sat there for about 30 seconds and the rpm's picked back up so i finished my last strip and headed for the shed. A few feet from the shed it stopped running and hasn't started since. It seemed like a fuel issue so i replaced the fuel filter .didn't help. So i replaced fuel pump and also new Carb. No start. It's getting fuel but replaced all the fuel lines when i put the carb and pump on. No start. So we checked and it wasn't getting any spark. Installed a new coil and spark plug and still won't fire. I tried pulling the kill wire off the coil which should bypass all the safety sensors but still won't fire. Ohmeter tested the coil and all the reading were in range on both coils that i had. Flywheel magnets are in place and strong because they suck the coil up to them with good force.
What else can i try , i don't want to keep cranking until i burn up the starter too. I even tried dumping a little gas down the carb but it wouldn't even fire once. I am lost. Thank you for your time.

 

[slomo]

Verify you have these. Air, fuel, spark and compression. Can't cut grass without them.

Couple homework assignments for you.

1.KEEP and remove OEM carb from engine. Break it down removing all small parts. Boil clean the carb on your stove top with water and those automatic dishwasher balls. Use a candy thermometer to keep water/soap temp at 200F. Boil for 30 minutes. Rinse well in clean water to neutralize after. Blow out with compressed air. Reassemble carb. Flip carb over and blow test carb needle/seat (fuel inlet pipe). Should hold 7psi for 30 minutes.
2.Remove fuel tank. Clean out 100% with compressed air. Install new fuel line, filter and shut off valve if you have room.
3.Clean block and cooling fins YEARLY per your engine manual. Remove top metal engine shroud exposing cooling fins. Neglect this and you will get engine damage.
4.Adjust valves per your engine manual yearly.
5.Decarbon cylinder and valves every 5 years or suggested interval in your engine manual. Neglect this and you will get engine damage.
6.Test ignition coil with old spark plug gaped to 0.250" or 1/4". Check for good blue spark. Check for spark if and when engine dies with inline spark tester.

I'd try in order 2, 3, 6 first.

All these new parts require testing of each and every one.

Hope you are keeping all those old OEM parts too. Most likely nothing wrong with most of them.

 

[Lou the mower killer]

Slomo ,
It would appear that nothing in your post is relevant since i posting in the original post that it WAS getting gas but NOT getting spark. I suppose that would mean that they were verified . But thank you for the response . Have an awesome weekend.

 

[bertsmobile1]

There were several ignition systems used on Kohlers
If your magneto has a single wire on it the pull that wire off and check for a spark
If it has 2 or 3 wires then it is one of the electronically controlled sparks and they are a bit more complicated to check
So best go to Kohler & download the engine service manual which is FREE
AFAIK the electronic sontrol units are all discontinued but the engine can be converted to a standard set up

 

[Lou the mower killer]

There were several ignition systems used on Kohlers
If your magneto has a single wire on it the pull that wire off and check for a spark
If it has 2 or 3 wires then it is one of the electronically controlled sparks and they are a bit more complicated to check
So best go to Kohler & download the engine service manual which is FREE
AFAIK the electronic sontrol units are all discontinued but the engine can be converted to a standard set up

Thanks , and yes I tried starting without the "kill" wire. The Kohler command has just the single wire magneto system. That's what doesn't make any sense. There can't be a broken wire because it doesn't have any, and both coils ( new one and old one) pass the Ohm test so it should have spark. Next thing I am going to try is possibly adding a couple extra ground wires from engine to frame . Not sure if that would matter but I can't seem to get any other ideas , I am all out. Especially since the starter is grounded and spins the engine over just fine. If it were a car it would have been fixed within a few hours , but not this mower. Thanks so much and have a great weekend.

 

[hlw49]

Could you have mounted the new coil upside down?

 

[Lou the mower killer]

Could you have mounted the new coil upside down?

Anything is possible at this point. I took pics with my phone before i disconnected the original one , but that doesn't mean the new one doesn't need to be flipped upside down. I am going to try it out in the next day or two when the rain stops... it is outside under a tarp. Thank you for the response and have a great weekend.

 

[sgkent]

I'd check the tank for gas again.

 

[Lou the mower killer]

I'd check the tank for gas again.

It's completely full. As mentioned in my post it is getting plenty of fuel.

 

[bertsmobile1]

From the top
1) you can not test magneto coils with a standard Ohm meter because what you will be reading is the Hall effect chip which times he spark
Cheap multimeters can actually pass enough voltage down the wire to fry the chip
2) were they genuine Kohler coils, quality parts from an on line retailer or shop front or a lucky dip coil off Evilpay or Ammozone ?
How are you testing the spark ?

The magneto is self energizing so if there is no kill wire on it and it is not touching the magnets ( or any other part of the flywheel then it must make a spark if it is good .