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Let me add to the list.
'98 Yard Machine with the Tecumseh 12.5HP. Was previously having trouble starting. Pulled the starter apart to find the magnets in pieces. Replaced the starter as well as the solenoid while I was in there. Changed the oil, too! :biggrin: Turned the key, the engine makes 1/4 to 1/2 of a revolution and then it locks up, with the starter being stuck in the engaged position. I loosened the starter to allow it to return to the disengaged position. Turned the flywheel of the engine by hand, so the engine isn't seized up. Retightened the starter and tried again, same results. Anyone have any ideas?

Just to be sure, is that battery full charged?

Yes, battery is fully charged and has the proper number of CCA's.

Read another thread concerning a B&S engine with the same symptoms. Someone commented trying to turn it over with the spark plug removed. Can I try this with my Tecumseh as well?

Pull the spark plug out and try turning it over. Post back results and engine numbers.

Pulled the plug and attempted to start, same results. Even jumped it off of our Camry just to be sure.
Engine is Tecumseh OHV125 206604B.

Are you saying that with no plug in the engine the starter would not spin it over?????

Rivets said:

Are you saying that with no plug in the engine the starter would not spin it over?????

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That is correct. I'll get maybe 1/4 turn on the flywheel then it locks down. Yet, when the starter is disengaged from the flywheel I can turn the flywheel by hand. Doesn't make since to me.:confused2:

I know that this manual does not have your exact engine in it, but I think it will be of some help to you. Go to this website and download it.

http://www.mymowerparts.com/pdf/Tec...-OVRM120-OVXLC120-OVXL120-OVXL125-695244A.pdf

With that said I would be pulling the starter and either bench testing and rebuilding or replacing it.

Starter is brand new. I actually bench tested it before I installed it (habit from working in the dealership) and it spun up great.

So, according to this manual (which, BTW, I saved. It's awesome!) I'm looking at either flywheel interference or internal engine failure. The latter of the two does not sound appetizing...

Ok, try this. Jump the starter directly, not going through the battery. Tractor parking brake locked down, negative jump lead to a good ground, positive jump lead to the terminal on the starter, no plug. If it spins, install plug, and lock the parking brake down. Choke on, throttle half way and see if it will start.

Jumped the starter directly, no spark plug in. Same results.

Time to check wiring. There might be a safety interlock switch, such as the seat/ operator presence, cutting deck engaged, and the parking brake? Address all those and then try and turn it over.
Let us know.

Grassbandit said:

Time to check wiring. There might be a safety interlock switch, such as the seat/ operator presence, cutting deck engaged, and the parking brake? Address all those and then try and turn it over.
Let us know.

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Would any of those malfunctioning allow the starter to attempt to start at all? The starter engages the flywheel and usually gets 1/8 to 1/4 turn before locking up.

SSomething is not right. Can you turn the engine by hand in the same direction forn two revolutions?

Just reread your thread and this popped out at me. You said you replaced the starter. Tecumseh had two different starter gears. Is it possible that the number of teeth on you new starter is different than the number on the old. Some had nine teeth and some had ten. Please check. This is not a wiring problem, because when you did a direct jump you bypassed the entire wiring harness.

Turned the flywheel by hand for four revolutions, no hang-ups.
Double-checked the number of teeth on the starter: 10, same as the old starter, which at least USED to start the mower.

I'm racking my brain here...

So am I. Can you put the old starter back on and try it or is it completely junk. Now, I'm thinking you have a bad new starter, possibly a broken magnet or bad brush, causing the problem. If you can rotate then engine by hand, I don't want to go inside at this time. Don't see a need yet.

Rivets said:

So am I. Can you put the old starter back on and try it or is it completely junk. Now, I'm thinking you have a bad new starter, possibly a broken magnet or bad brush, causing the problem. If you can rotate then engine by hand, I don't want to go inside at this time. Don't see a need yet.

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Old starter is completely junk. Could be a bad new starter (I've seen that happen before with automotive parts).

RenegadeStang said:

locks up, with the starter being stuck in the engaged position. I loosened the starter to allow it to return to the disengaged position.

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That starter pinion gear should not be binding in the flywheel.

If the starter is mounted so a shim of a few thousandths can be added to move the starter away from the flywheel a small amount I'd be trying that.

SandburRanch said:

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That starter pinion gear should not be binding in the flywheel.

If the starter is mounted so a shim of a few thousandths can be added to move the starter away from the flywheel a small amount I'd be trying that.

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Hmm... I'll give that a try. It's worth the shot, I'm out of ideas! :laughing:

The starter part number should be 730326. I hope that is the one you have. Never thought about what the last poster said, but if the legs on the starter are bent wrong, that would cause the problem and shimming will help. Thanks for catching that SandBur.

Success! Shimming the starter allowed the starter to turn the engine over with the spark plug out. However, I am still experiencing the same problem when I put the spark plug back in.

Great, one problem solved thanks to SandBur. I would now look at valve clearance. This website has a manual which should help you in doing that. I know that it does not include your engine, but the clearances are the same as a 120

http://www.mymowerparts.com/pdf/Tec...-OVRM120-OVXLC120-OVXL120-OVXL125-695244A.pdf

RenegadeStang said:

Success! Shimming the starter allowed the starter to turn the engine over with the spark plug out. However, I am still experiencing the same problem when I put the spark plug back in.

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This is where an amp gauge is handy. It will tell us if the starter and battery are doing the very best they were designed to do or if there is another problem like compression relief not working because of valve adjustment on certain engines.

In my testing of an engine of that size I've found normal cranking amps. to be in the neighborhood of 100 and abnormal cranking amps. to be close to 300.

If I had a thousand of these gauges pictured I'd give everyone on this forum 1 but this is all I've got and it came in an auction box of just STUFF.