One more note, the lights won't turn on either and when it was working, I could get the lights to turn on no problem.

12.6V is a "normal" charged battery, so your battery isn't fully charged or bad.
You should still get a click from the solenoid though.
Check for a blown fuse.
Also, make sure it's in neutral, deck disengaged and you are on the seat.
Not sure what safety devices your mower does or doesn't have, but those steps should cover all of them.

The fact that your voltage "holds up" under load means the starter solenoid isn't getting "activated. Blown fuse seems to be logical. Safety switch would too.

Try jumping 12V direct to the small terminal on the starter solenoid. IF the engine cranks, it eliminates the solenoid & starter from being the problem.

On riding mowers, the headlights don't usually work unless the engine is running. There's a separate AC lighting circuit of the alternator. Saves the trouble of having to use a diode there too.

You might at least try to identify the engine brand, model etc. On a Briggs, the code is the DOM, yymmddzz. Other engines use the seria # etc.

bill, thanks for the quick reply. Sorry I didn't add the extra info I knew. 1st, it's a Briggs and Stratton twin 16 hp engine. I think I can find the serial number for that if that would help. And last night (actually this morning), I went to check and I do indeed hear a "click" when I turn the key. Also, I have tried jumping the lawn mower, but just buy putting the terminals right on the battery. 12.2 is a little low, but wouldn't I at least get cranking?

Okay, good to know that the lights don't go on unless the engine is running. I thought that might be the case.

Now...the starter solenoid. I *think* I've identified where that is but I'm not sure. Any tips on how to identify it?

The starter solenoid will have the + battery cable attached to it. There will be another large terminal going from it to the starter motor.
That's where knowing which engine would let us know what type of solenoid you have. Some are attached to the starter motor itself and actually engage the starter drive gear with the engine, while others (yours I ASSume) are basically a relay switch.
B&S 16HP Twin? There's V twins & opposed twins... It's kind of like saying Chevy V-8.
MODEL Tells which engine
TYPE tells us some of the variations of the basic model.
CODE tells when it was built YYMMDDzz, Sometimes, that's important when ordering parts or other pesky variations that type doesn't cover.

Looking elsewhere on the net, I see that 12.2V means about 75% charged.

Also, You could remove the spark plugs, ground the cables and then try cranking.
IF nothing else, you could find out if your carb leaked and filled the cylinders with gasoline, thus hydro locking it.

Have you cleaned ALL the battery cables, including grounds?

Okay, I'm almost 100% positive I found the solenoid starter. The positive cable from the battery is going down to one of the screws of an object that looks exactly like this

{{gwi:132894}}

which can be found on this page

http://www.briggsandstratton.com/maint_repair/parts_supplies/details.aspx?pid=745000MA

The ground from the battery is attached to the engine housing and near the part that I'm sure is the starter, another cable is attached to the other screw and also attached to the engine block (if that makes sense).

So my thinking was to try and eliminate all of the possible switches (seat switch, neutral switch, etc) and figure out if the starter was the problem. So I first connected jumper cables to the battery and tried to connect them directly to the starter. Would I be correct in saying that it should have started up right then and there? Anyway, it didn't so for good measure I sat on the thing and turned the key, which seems to negate me connecting terminals right to the starter. Anyway, that didn't work either.

Taking it a step further (and trying to eliminate the battery as the problem), I used my battery charger/jumper. Again, nothing. Again, I took it a step further and tried sitting on the seat just for good measure.

It would seem as though the starter is bad, no?

One last thing. I got my multi meter and was able to get an equivalent reading between the two terminals of the starter as I got from my battery. I'm learning as I go along here, but shouldn't there be no reading between the two terminals until I turn the key? Then, jumping the starter makes sense to me. Otherwise, what did I really accomplish by jumping the starter if it already has a voltage drop?

I'm going to take pictures and post them in a sec. Thanks for your help!!!

Okay, I've taken two pics. Not sure how much they're worth. I can take more if you need better angles.

{{gwi:132895}}

In the first, it's just an overhead shot of the engine. The black attaches to the engine housing and the red (well faded, so it's orange now) goes down underneath to the next pic.

{{gwi:132896}}

Looks like the starter to me. The faded cable on the right is the positive from the first pic and the red cable on the left is attached to the engine block on one end and the starter on the other. Now again, I get the same voltage reading across the terminals of the starter as I do the battery. Shouldn't I get no reading across the terminals? Shouldn't turning the key create the voltage across the starter? Anyway, I'm doing more detective work here. Any help is much appreciated!

Going back to the original post. My curiosity is
killing me.....how do you 'mistakenly' buy a big
orange riding mower?

Ibpod, to answer your question, I'm new to riding lawn mowers and always had a self propelled. I finally got sick and tired of mowing my modest 1/2 acre plot and decided to pick a "cheap" $160 lawn mower on eBay. From the looks of things, the engine not starting isn't the only problem. So I decided with the amount of money I'm going to spend on it, it made more sense to buy a new one. However, I should at least know a riding lawn mower well enough to figure out why it won't start and that's why I'm still trying to fix the old one.

Ideally, I'd like to get it completely working again and sell it. I'll probably lose money doing it, but it will be a learning experience.

Bill, I'm going to attempt to follow your directions tomorrow. Since my new lawn mower just came today, I've banished the old one to the side of my tool shed.

Now I understand. I guess I just read into it
the wrong way. Thanks, and good luck.

hello i have a craftsman 13.5 hp elec start 30" 5 speed . wont turn over by key. will turn over with wire from battery + to starter also will turn over with screw driver across two connections on solenoid. i cut wire to safety on seat and spliced together wire wire.15 amp fuse is good . its the only fuse i know about. i cleaned connections to battery and negative ground. i push clutch all the way down. mower attachment not engaged. will not turn over by key. ???

Need some insight...my Ariens rider (Briggs & Stratton engine) will not turn over but if I take the spark plug out it will turn, obviously not engage. It almost seems like something is getting hung up on the spark plug. Any insight will will be greatly appreciated.

Most likely CC, your valve lash is excessive and needs to be adjusted. You can search in the rider forum for instructions or have it inexpensively done at a shop.

Ok I have an ariens zoom 2350 that won't click or start. I've changed the solenoid the battery and spark plugs. And still nothing. Please help me I'm new to these zero turn mowers.

There should be a fuse, check this . You could try turning the engine , even enough to rock the engine back and forth via the flywheel screen. Park brake on? PTO switch pushed in? Report back.

Yes park brake is on pto switch is pushed in all the safety measures have been

Checked

Ok did the fuses. Now clicks but won't start.

Can you turn the engine by hand? If so, possibly jump direct to the starter to see, if you can get at it.

Yes it will turn but stops. Is that

Ok, mine will turn but only about an inch, then return to the original position as soon as i let off the key. Bypassed the control module and i cant even get it to move at all with the key. But as soon as i connect the bypass wire, it does that same one inch turn and releases as soon as i disconnect the wire fuel and oil are good, will get spark tester tool later but any ideas until then?

Battery is good as well

Its the compression release on the camshaft look up or google briggs and stratton compression realese repair