Hmmm...NormK I thought all carbs leak at one time or other but Tecumseh when properly working don't leak or at least all that I have repaired. Now their rubber needle seat do tend to go bad but the Briggs carbs that using the same system does too.
As the OP coming up a cast iron heavy flywheel PN vs the lightweight flywheel in the pictures it comes down to what is the spec number is for that engine and if someone in the past changed it out as many of the techs here appear to do experimenting or making will do repairs. It maybe even that changed out part with the engine spec number with a different spec engine like many DIYers here do with the Briggs tins that have the engine info on it making it a guessing game later. Anyway always lookup parts by both the model and spec numbers.
I not downing experimenting even I do it time to time on expendable equipment. I even seen an old 12.5 hp L head Briggs to have tons more HP by just setting the cam to crankshaft timing off by one tooth. I just don't remember which way I had set it as it was 30 yrs ago now. I did use the engine for a very long until the transaxle went South to the graveyard. That was when I lied to by a local that the part that I was needing was NLA but 10 yrs later I found out that was not the case.
