MTD LT542G Tecumseh 18hp will not turn over.

bogey boy

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Hopefully someone can point out the obvious thing I am missing here. My battery was stored in the warm garage and charged all winter. I put it in a few weeks ago and fired up the mower. I mowed around a bit then parked it. I went out last week to actually mow and it would not turn over at all. I hooked up the charger but it said full charge... I have tested what I can think of. The solenoid activates when I touch it with the charger leads but no starter spinning. I can use the charger directly to the starter and it spins but doesn't engage with the motor (maybe not enough amps from the charger I assume) I have checked the 3 safety switches mechanically, they are all depressed. I have not tested them with multimeter but I assume they are either touching or not, they don't appear to be broken. Is this a bad assumption? I replaced the ignition switch last summer and it looks nice and clean and appears to turn appropriately. I have 12 volts between the green and red wires on the back of the key. I tried to jump from the red to the orange wire to the solenoid but nothing. Maybe I need to tie in some of the other circuits on the back of the key before it will work that way? The only sound I can hear when I connect the battery or turn the key is a muffled click, or tick from the front of the engine somewhere behind the air filter, I have not torn apart the engine to see what it is in there making that noise but it is clearly not the solenoid (in back of tractor) not the starter (other side and back of the engine). I am feeling like it is the key switch but don't know how to bypass the key and try to start to rule that out. Any ideas would be greatly appreciated. Thank you anyone!
 

EngineMan

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Bridge something between the two big leads on the solenoid and see if the starter works, if it does, you may have a bad connection on or around the solenoid, make sure the ground wire or the body of the solenoid is clean, if the starter works by bridging the two big leads you may need to replace the solenoid.
 

bogey boy

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So I made some progress today. I had already tried to jump over the solenoid and it hadn't worked. I took off the starter played with it for a few minutes, maybe needs a bit of lubricant? But still functioned. I fired it with the battery and a jumper wire then put it back together. I tried again to jump over the solenoid and it fired right up. Of course I had turned the key on this time (might have forgotten that step when I tried last time)...she ran a bit rough until I realized that I had pulled 1 of the spark plugs to look it over and forgot to put it back in. After fixing the spark plug missing problem, I jumped from the battery to the starter tab on the solenoid and off I went to get the lawn mowed. After I finished, I shut it down and turned the key to see what would happen. Nothing again. I am now wondering if the key switch has failed already and I need to replace it. But at least now I have a week or so before I have to mow again and I will have more time to play with things. When I figure it out for sure I will come back and post. Thank you for the suggestion, it made me retest something, and it ultimately worked for the short term.

Thanks
 

EngineMan

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I would replace the solenoid before replacing the key switch. if the starter is working alright.
 

Ronno6

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Possibly a switch in the safety circuit??
Seat switch, or parking brake switch?

Are you sure all the controls are in the correct position?
I once had a secretary who was in a panic because she couldn't get her new car into gear the Monday after she purchased it.
When I asked her if she was stepping on the brake pedal.....................
 

bertsmobile1

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Solenoids are a service item and need to be replaced from time to time
On the bottom of the solenoid are 1 or 2 small terminals, these are the trigger wires one is + the other is -.
If there is only 1 wire it is + and the body of the solenoid is the ground contact.
This type suffer badly from water wicking under the base and corroding the zinc plate so you end up with a bad ground.

From what you have said already, sounds like you had a bad contact on the starter.
Test the solenoid by jumping to the trigger terminals.
If the solenoid clicks ( they should really KLACK more than click ) and the starter does not turn the solenoid is duff internally and needs replacemet.
The ones with 2 trigger wires are not polarity sensitive so either way is fine.

I have a few short wires with female spades each end I use for do this with ( and bypass other switches for the purpose for testing ).
IF yours is behind the battery, under the guard make up some longer ones so you can poke then up through the battery box for doing this test.
 

Travlitt

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Hopefully someone can point out the obvious thing I am missing here. My battery was stored in the warm garage and charged all winter. I put it in a few weeks ago and fired up the mower. I mowed around a bit then parked it. I went out last week to actually mow and it would not turn over at all. I hooked up the charger but it said full charge... I have tested what I can think of. The solenoid activates when I touch it with the charger leads but no starter spinning. I can use the charger directly to the starter and it spins but doesn't engage with the motor (maybe not enough amps from the charger I assume) I have checked the 3 safety switches mechanically, they are all depressed. I have not tested them with multimeter but I assume they are either touching or not, they don't appear to be broken. Is this a bad assumption? I replaced the ignition switch last summer and it looks nice and clean and appears to turn appropriately. I have 12 volts between the green and red wires on the back of the key. I tried to jump from the red to the orange wire to the solenoid but nothing. Maybe I need to tie in some of the other circuits on the back of the key before it will work that way? The only sound I can hear when I connect the battery or turn the key is a muffled click, or tick from the front of the engine somewhere behind the air filter, I have not torn apart the engine to see what it is in there making that noise but it is clearly not the solenoid (in back of tractor) not the starter (other side and back of the engine). I am feeling like it is the key switch but don't know how to bypass the key and try to start to rule that out. Any ideas would be greatly appreciated. Thank you anyone!

That muffled click behind the air filter is probably the anti-backfire solenoid on the carberutor(s)
 

bogey boy

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Quick update...still having no reaction to the key turning. I replaced the solenoid just for fun. Still nothing. I have a trusty wire sitting next to the tractor so I can jump from + of battery to the starter side of solenoid and mow my lawn. I thing next I need to test continuity on the orange from key to the solenoid. I assume all of the safety switches are working correctly since it will run. The key does work to the extent that I need it on to run, I can turn it back and press the button to disable the reverse kill feature and I use it to turn off the mower after I am finished. I feel like the issue is the orange wire to the solenoid from the key but cannot see an obvious problem with it. Maybe I can cut it, make a jumper wire that runs back to the solenoid and try that. That should isolate the problem to the key or wire.
 
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Yes a trusty wire does come in handy always.......

We outboard and small engine techs have a remote starter to make our work easier for us............
 
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