Small Engines (Lawn Mowers, etc.): B&S Engine wont start, weak spark, ring gasket, mtd products

Question
Evening!

I have a Snapper Hi-Vac push mower that I have had about 20 years, though its not used a lot usually, and sat for the last year unused. Never had a single issue in the past with it. Now it refuses to start. Seems to be good compression. I replaced the fuel line and filter today due to age. I also replaced the spark plug with a new one, and checked the coil as well. It read around 4600 Ohms on the voltmeter, which should be good, but, holding the plug wire from the plug about 1mm its a faint spark. Any farther and there is no spark. Just barely a tickle to while holding the wire. Also tried it with and without the kill switch wire connected. The engine is a B&S 124707-3114-01 (numbers above the head on metal shroud over top of engine), which I believe is a Quantum, though the engine only says, built by B&S for Snapper.

My question is, what do I need to do to get this engine running again, or better yet, what is keeping it from starting? I'm thinking either the coil is weak, or its time for a rebuild.

Second, (I doubt the engine is bad, but worse case) is there a drop in replacement from B&S or would it need a rebuild? Mower is in great shape, no rust, etc, always stored inside and washed/dried.

BTW, Ive grown up around and always had Snapper, and older Cub Cadet (pre-MTD) products, so I would like to stick with what I know.

Answer
The engine should have electronic igntion so weak spark is not an issue...usually.  Only found one weak coil on a Briggs in 20 plus years.

To get it running I'm betting the carb just needs a good cleaning along with some internal parts, inlet needle and seat plus a bowl o-ring gasket.

Did you try priming the engine to see if it will fire?  This is the first thing we do with all products that come in for repair.

As for a new engine, it should be a piece of cake.  I replace several a year on old Snappers...older Snappers are better than the newer ones they are currently selling.

What is the crankshaft output (blade side) diameter and length.  The diameter should be 25MM (1 inch) or 7/8 inch and the lenght should be  3 and 5/32 inch.  Very common crankshaft.

Let me know if the engine starts by priming.
Eric