Okay, update time, although a bit premature (you'll see why).
I basically disassembled this sucker down to it's jockeys, and have found nothing wrong with it.
- It's getting a good, consistant spark
- It's getting air (removed air filter)
- the carb is clean
- the fuel is new (not mixed - it's a 4 cycle)
- It seems to be getting fuel, but with that overly complicated carb, there doesn't seem to be a way to tell if it's getting enough, althought there was fuel throughout all of the sections/parts of the carb, so it seems to have traveled to the main jet, and the main ject is clear. But when trying to start it unsucessfully, the plug does not seem wet when I pull it out, but it does seem to be wet in the air chamber
- The flywheel key is fine (no removable key like I'm used to, but a normal cutout in the shaft and the flywheel has a permanent "key" molded into it. See below for more on this.
- I've adjusted the valve gaps to exactly the middle of the range specified in the manual
I say this is "premature" because I took the flywheel off and reassembled everything the other night, but have not tried to start it again. I did check to make sure I'm getting a spark, so the ignition magnito is working and the cutoff switch is not shorted. However, other than the valve gaps, I have not cleaned, changed or repaired anything, so I doubt it will start (I have tried since I adjusted the gaps)
If this thing doesn't start, I'm getting to the point where it may find it's way to the landfill or to a repair shop as a donation (let him make money on it if he can fix it). If I do remove it from my sight, I'm going back to 2-stroke. I know I can fix those.
I understand that a small engine like this is a pretty simple creature. All it needs is air, fuel and a spark (at the tight time), so I don't get why this thing won't run.
About the flywheel: The flywheels I have removed in the past, have been a friction fit over the shaft, and have been somewhat difficult to remove (needed to pund the shaft out of the flywheel with a hammer), and when reassembled, have been a very tight fit on the shaft (usually needed hammering down). This flywheel is held onto the shaft by a collar/spacer, then a clutch that is screwed onto the shaft, which holds the flywheel down. When I removed the flywheel, it took some prying (not too much, but it did not just lift off or come off when I held the flywheel and hit the shaft with a plastic mallet). When I put it back on, I tightened down the clutch, then removed the clutch just to see if the flywheel stuck to the shaft the way it was when I first removed it, but the flywheel easily lifted off the shaft with no resistance. So I'm wondering if the flywheel hadn't slipped just a bit on the shaft, because the molded-in "key" is not very deep. I'm sort of hoping this is the case, and the timing of the spark was off because of that. Note that I didn't see any scratches on the shaft to indicate that it slipped.
We'll see what happens when I try to start it. I'm not very optimistic.
Thanks for all the help fellas.