I should add that I can see and feel the solenoid click hard (so hard in fact that it almost rocks and dust falls from it). So what could my problem be? I really want to get this fixed...

First thing is to clean the battery cables (both ends).
If that doesn't fix it, measure battery voltage when trying to start and report back.

If the battery really is charged (check the voltage again after it sits over night), then the problem is one of the cables connections.

Remove the negative battery cable.

Next remove the positive battery cable on both ends (e.g. at the solenoid and at the battery. Scrape or sand the metal and replace.

Now do the same for the cable from the solenoid to the starter.

Now remove the negative cable form the frame, clean both ends and then replace it.

This will probably do it.

Wow you guys are great.

Out of curiosity I tried the battery voltage when I turned the key, nothing changed. I then began removing the cables and sanding/wiping clean all connections. I carefully re installed the connectors (thanks wheelhorse) and made sure everything was nice and snug (not over tightened but tight).

I crossed my fingers and turned the key and she came to life instantly! It might be my imagination but it seems to start faster and run stronger (Briggs twin cylinder engine if that makes any difference).

All in all for a gift tractor the ol' Simplicity is serving me well (yes itÂs the 85-85 model). I'll continue to baby her as my father in law did (over 1500 hours on the mower and it doesn't use a lick of oil and has not been rebuilt). Yeah he is good to his equipment and I have all of his habits.

Well I'll stop rambling, I sincerely thank you guys as now I can begin to enjoy my vacation without worrying about getting the mower going in time for the next mowing.

I sure do like the Simplicity!

The lights also seem brighter (but then again maybe it's my excitment to have her running again)!

My thanks again!