If I am trying to get something running & there seems to be more than one potential problem keeping it from working, I try to eliminate as many as possible. If I suspected valve adjustments were too tight, I would adjust them but wouldnt even try to get them exact, just loose enough to not hold valves open, As soon as I get it started I would worry about getting things just right. Timing I would set in a mild position, not very advanced at all. If you have spark I would guess the ignition is wired okay.Now, you gotta get a fuel air mix in the jug, squeeze it & light it off. I would pull the plug & crank it & see if I could tell if there was a decent mix in there. If so, look at the plug against the jug & check for spark. Then stick a finger over the plug hole & see what kinda compressioin it has & pull the air filter & stick a hand across the intake & see what kinda suction it has. If all that stuff seems like its good enough to run, even if it seems wimpy, will it run at all? Then I would have to check the timing out.That kick starter will be handy there. With the plug against the jug bring the piston to TDC & see if it sparks there or if its off so far it wouyld be impossible for it to run. You should be able to work thru it. I have zero experience on these engines & maybe I am off by a mile, but if it was in my driveway, thats how I would go at it.