I think you will find all Honda engines have the flywheel retaining nuts held by right hand threads. Because the flywheel is on a key, there is no advantage in having a left hand thread. Also, the main issue here is if the engine stops suddenly due to having hit a waterpipe, in which case the flywheel moves clockwise and tightens the thread. In any case you can normally check the thread since the crankshaft protrudes through the retaining nut for at least one turn of the thread.
I agree that on an ancient engine which has gradually lost spark intensity, there is a good possibility that the problem will be that the points have closed up. (The points gap would have to be down to much less than 0.010" before this would happen.) However it is fairly difficult to judge weak spark conclusively unless there is a standard sparking test that you have been doing over the years and now find the machine cannot pass, whereas it did pass the same test previously. Briggs have two such tests: a 0.060" spark gap, and a 0.166" spark gap. Honda does not have an equivalent test. I suggest that before pulling the flywheel you try a 0.060" test gap external to the engine, in place of the spark plug. If it will not spark evenly across that gap, it is unlikely to fire the mixture consistently with the standard plug gap. In the limited testing I have done, Honda's electronic ignition at least, will not fire across a 0.166" gap, and it is not a good idea to try it because it tends to be hard on the electronics. The tests I have done on a Briggs engine fired well across the 0.166" gap, but when I tried it in series with the spark plug on a running engine, it stopped firing after just a few seconds. See why I don't want to do a proper test series on a Honda, given the prices of their spare parts?
