Problem with 17.5 hp tecumseh riding mower

[Herz]

Hello guys,

I have a 17.5 MTD riding mower with a tecumseh motor. Recently the tractor has been getting difficult to start, but would if I jumped it with a battery jumper. Then it would not start at all. I jumped over to Autozone and they tested the battery and it was bad, so I picked up a new JC duralast battery.

I installed it and it would not even turn, no noise nothing. So I had an idea to disconnect the battery and plug my jumper directly to the starter and ground it. It made noise like it wanted to turn but wouldnt. I took the starter off and over to my local small motor supply store. I told the guy the problem, so he jumpes it off a battery and said that the gear is stuck thay he could clean it up and get it working. I install the start after he demostrates that the gear is turning and the rest of the starter is good. Still nothing! My guess is it is a bad ground or could the starter actually be toast?

 

[JimPghPA]

Does the motor turn freely when you remove the sparkplug and do NOT have it in gear?

If the motor is frozen you can rebuild starters and put new batteries on until the cowls come home and it still will not start.

 

[Herz]

I'll give it a shot, so remove the plug then try getting it to turn, i'll post with what I find.

 

[Herz]

Engine is not seized and rotates freely, any other ideas? Could this be a solenoid or fuse?

 

[meep]

tap jump pack + lead directly to starter power and see if it spins faster. if so, then solenoid is faulty. if not, starter is weak or engine is putting excess drag on it.

if solenoid ok, starter ok, then it's wiring between batt/solenoid and/or grounds.

 

[Herz]

Ok, i had some time today to work on the tractor. I did alot of stuff.

First I took the battery out and jumped the starter wile it was on the engine and the motor turned, fan on top was spining. So the starter is indeed good and the motor is not seized. I took a look at the wiring under the seat, it all looked good. I took the motor ground off and cleaned it with a stainless steel brush. I also cleaned the battery posts, and battery wires with the brush. I went over to my tractor supply and picked up a new solenoid for 10 bucks, only difference is it has 2 ground leads instead of only one. So I grounded a wire to the frame with a screw, plugged everything in and at first the new solenoid was making a rapid click noise. Then it turned into one click everytime I turned the key. I took a screwdriver and placed it over each of the positive posts on the solenoid and it made a single click.

I do not know where to go from here?

 

[boraticus]

Have you tested to voltage of the new battery? It should be well over 12 volts. A fully charged battery is around 12.7 volts. A battery reading 12 volts is only 25% charged a battery reading 11.9 volts is completely discharged. I assume that you've checked all electrical connections for corrosion or possibly broken wires?

Sometimes multi strand wires will begin to corrode and/or break at connectors. These wires are usually heavily shielded and make it difficult to detect wire integrity under the shielding. The starter will put heavy demand on the battery and wiring. Hence the necessity for robust wires in good shape and a well charged battery.

There are also a number of fail safe switches on yard tractors. There's one under the seat, one for the foot control and another interrupter for the blade drive. All those should be inspected as well.

Electrical problems can be very difficult to nail down. Slow, methodical and thorough inspection is required to eliminate possibilities.

Keep at it. You'll find the problem sooner or later. Let us know what it was.

 

[Herz]

So I tested the new battery and it read 12.6volts, and keep in mind this is after jumping the starter and other connections multiple times. So I connected the battery directly to the solenoid on the starter side and it tried to turn engine. To me that meant that somewhere on the battery positive it was faulty. I cut some of the insulation on the battery positive cable and there were several strands of wire that were broken. I cut it off and replaced with the closest conductors I could find and a new post. I spliced it with a waterproof butt connector, and new battery post connector and bam, started right up.

 

[kcfx4]

so the starter (not jumping) turns the motor over wo plug? oh heck i should have read on, you fixed it! ill have another beer lol

 

[boraticus]

Originally Posted By: defektes
So I tested the new battery and it read 12.6volts, and keep in mind this is after jumping the starter and other connections multiple times. So I connected the battery directly to the solenoid on the starter side and it tried to turn engine. To me that meant that somewhere on the battery positive it was faulty. I cut some of the insulation on the battery positive cable and there were several strands of wire that were broken. I cut it off and replaced with the closest conductors I could find and a new post. I spliced it with a waterproof butt connector, and new battery post connector and bam, started right up.


Good to hear you resolved it.

In my decades of experience with new and old equipment, I've found that the normal source of electrical starting problems is usually right around the battery. Either poor ground, loose connection, corrosion, bad battery or broken conductor wires hidden under the shielding.

I usually test the battery first then look at terminals and the heavy leads.