Can I adjust the clearance on these valves?

Sorry I've been so long away from this thread. Days off work and then a run of night shifts. I will admit the night shifts are much more pleasant than the hot days. It's been 36 deg in the shade so I think that is 97 or 98 for you, and humid. But we get that here in the wet season so it's not like this is a surprise.
The Toro that would not start. Now runs.
I did not fix it I gave up, when I realised that with the days off and nights it would be more that a week before I got hands on it again I decided that was too long for it to be off line.
Called the dealer in town and 3 days later they sent a trailer out to pick up the Toro.
I wasn't there but the scene has been described to me several times. The man picking it up said he would try and start it to get it onto the trailer as the winch was not working.
The engine spun over well as it's been doing and he looked at it and immediately said that smells a really rich fuel mix.
He checked the carb and someone had undone the 8mm bolt on the choke cable applied full choke and retightened the bolt.
The engine was drowning, yep looks like it was deliberate, looks that way.
So 1 fast adjustment and it started right up.
Apparently it ran just perfect for the next 4 days, in fact till yesterday when it died again.

the only thing you need to watch for with the neon blink testers is they can and do give a false positive if some cases. they will still show spark if the plug is internally shorted to ground.