Follow up.....had the battery tested and is OK. Hooked up remote starter button and cranked engine, no spark. Disconnected white wire to coil had spark, but did not start. Will check wiring to clutch switch and blade engage switch in accordance with mowie's advice to to other Craftsman/Kohler problem.

Don't favor mownie over bill kapaun!
Bill is perfectly competent and can find his way around circuit as good as they come.
Basic differences comes down to I have a big mouth and therefore use more words. :^)

Mownie, Tom Plum & myself tend to be "pretty adequate" on Craftsman tractor electrical.

Do you have a copy of the OWNERS MANUAL as I asked?
It'll be invaluable for you to look at the schematic for at least part of the issues! You don't need to be an electrician!

Did you try jumping 12V to the SMALL terminal of the starter solenoid?
IF so,what was the result?

We have a purpose to our questions!
IF you answer them, we'll get the problem resolved much faster, rather than having to ask repeatedly.

RE SPARK-
Disconnect OPR#1 and retest with the kill wire connected to the coil.
Spark or not?
IF spark, it's not getting 12V to pin 85 of OPR #1 through the seat switch.

I've got 8 gallons of house paint and only 1 applied, so mownie may have to interject himself rather frequently.

As an afterthought-
ALSO-
Check the connector to the key switch.
A bad connection there (or bad/incorrect switch) may be causing ALL your problems!
OR
Blown fuse/bad connection to fuse between Battery + and key switch.

This post was edited by bill_kapaun on Wed, Aug 28, 13 at 17:46

"Mownie, Tom Plum & myself tend to be "pretty adequate" on Craftsman tractor electrical." I dunno Bill. Electrical theory does not always come easily through a computer screen. Now were were we? Did anyone say if this was a 240 V or a just a 120?

OK...didn't mean to favor anyone all of you know more than I do or I wouldn't be asking for help. Will follow bill's post starting at the beginning as above.
1-I have the OM and the Kohler engine manual plus a spark indicator and Ohm meter.
2-Jumped 12v to the small terminal-engine cranked (Ign off.kill wire connected) no spark
3-Disconnected OPR#1, kill wire connected, no spark w/ign off, spark w/ign on
4-Checked key switch connector...OK (terminals are clean, used two different switches I know are good)
5-Checked fuse and connection....good
Note: with just kill wire disconnected there is spark

With the KEY OFF-
The Kill wire is grounded.and thus no spark.
Kill wire is M terminal of the key switch. When OFF, it is connected to the G(ground) terminal of the key switch.
(notice the "truth table" on the lower left of the schematic. It shows the connections in the various key positions)

Your test #3-
IF no spark with OPR installed, check the wiring from the key switch. L terminal.

When ON, there should be 12V to the seat switch.
When occupied, the seat switch is closed and allows the 12V to go to pin 85 of the OPR. (schematic shows OPR with no voltage at pin 85)
When pin 85 gets 12V, it switches connections from 30 & 87A to 30 & 87,
87A is part of the kill wire.
Thus, when the OPR is activated, the kill wire is ungrounded.

There may be a problem with the seat switch.
You can temporarily JUMPER it to see if you get voltage to pin 85 of the OPR.

Forgot to addressthe no crank issue.
Maybe a separate post for a separate problem might keep things less confusing.

When the key is in the crank position-
S(solenoid) terminal receives 12V from the B(battery) terminal of the key switch.
It then goes through the brake/clutch switch (pedal pushed) and then through the attachment switch (OFF) to the small terminal of the solenoid.
IF the key switch & connector are good, the problem has to be the brake/clutch switch, attachment switch or a bad connection.

Thus my though about a bad key switch/connector.
A bad key switch or connector could fail to provide 12V to the S terminal AND the L terminal.

You might want to verify you are actually getting 12V on the key side of the fuse.

Test #3....There is 12v to pin 85 in the on position.
Not to be too stupid here but I am having trouble locating the pedal switch. Assumed it was underneath the frame but I haven't located it yet. Would have to check it first before checking the PTO switch, correct? Have verified 12v on the key side of the fuse, fuse itself tests OK. I guess next is the brake/clutch switch if I can locate it.

To be honest, I don't know where it is since I don't work on them or own one.
It "should" be a WHITE wire from the S terminal on through to the solenoid.
You could work backwards from the solenoid to see if you have 12V at the various points.

EDIT-
IF pin 85 of the OPR has 12V, it should click if pin 86 has a good ground.

This post was edited by bill_kapaun on Fri, Aug 30, 13 at 18:43

I believe the switch is situated on the RIGHT side of the tractor.
Follow the foot pedal rod from the left pedal over the the right side of tractor (inside frame). The switch should be mounted so that the plunger is actuated by a surface on the plate that has 2 rods coming from it and heading toward the transaxle.

OK found the brake/clutch switch (in front of my face) tested good. PTO switch did not. Ordered 2 switches, which has taken awhile hence the lag. Replaced the PTO switch and it now cranks. Started and ran rough, ie missed. Sprayed small amount of carb cleaner directly into carb, it fired and ran like it should, cut off after about 30 seconds, would not restart even with a shot of carb cleaner. Possible sticking valve? Spark checked with spark tester. Interesting having two problems at once, but you guys solved one. Thanks....maybe I need a new lawn tractor.

It may be about time to pop the valve cover and look at the valve train for signs of unequal valve height (how far up the valve stem rises when the engine is turned by hand).
If one of the valves does not rise as far as the other, a valve seat may have come out.
Does the engine seem to spin faster than usual when cranking?
Hear any kind of hissing or wheezing sound from the exhaust while cranking?
Can you still "hear" the characteristic thump sound of the compression stroke while cranking or just the starter just seem to make a monotone, steady spinning sound like it isn't under any load?

Popped the valve cover, valve height equal. No fast spin, no hissing, hearing the compression thump. However, I did see the exhaust opening slightly right after the intake and then opening as it should during the exhaust stroke. I did not see a cam on the engine illustration. Having rebuilt small 4 cyl engines before I assume the crank is providing the valve lift on these small single cyl engines? The exhaust going down twice is a little baffling to me.

They certainly DO HAVE a camshaft.
What you observed with the exhaust valve rising slightly after the intake valve closed is caused by the action of the compression release mechanism (which is part of the camshaft).
Kohler release some compression out the exhaust valve whereas Briggs uses the INTAKE valve on most of their engines.
Confirm that the throttle plate and choke plates in the carb are not stuck shut because your valve train sounds to be in good order.

Yes there is a camshaft as you point out. Don't know why I missed it in the OM, but I sure did. Ill. #6. I hate getting old. Anyway I took the carb off, cleaned and checked the fuel shut off solenoid and made sure the choke/throttle plates were free. Seems the problem to this point is the engine needs more choke, much more than before these problems. Everything is working fine for now I appreciate all the help and now will move on to my other LT with the Briggs. I have a lot of info from this forum to get going. Again thanks....

Ooooops.....problem not quite solved. After getting things back together with new PTO switch, cranking good, starting good I find engine will cut off once engaging the PTO. Do I have a wire crossed or perhaps the clutch/brake switch is also bad? I have tried engaging the PTO with engine running, pedal up or down, same problem.

Back to OPR #1
Disconnect it.
Does the problem go away?
IF it does-
Look at the schematic-
The OPR must receive 12V through the seat switch to "activate" and disconnect the kill wire from pin 87A to pin 30 (ground).

I checked this before and there was 12v. However, I could not check it again as the engine refuses to start again. It has air, fuel and spark (spark tester used), but will not fire even with carb cleaner. It's probably time to get a new one. I have to go borrow the neighbors again. Can't test the cut-off problem until it at least starts w/o using the PTO. They shoot horses don't they?