Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

I don't have the exact model number handy, but it is the 8/24 from 1995 that a high end power equipment dealer would sell. I.E., not from home cheapo.
I live north of Syracuse, and get HAMMERED with snow. After 12 or 13 years, the engine is getting tired. It is funny, after using it, when shutting it down, I set it to idle, and turn the key off. While it is spooling down, I can pull my glove off, and point my finger at it and pull a "trigger". Bamm. Every time it shuts off, and comes to a complete stop, it backfires. (Exhaust valve?) Every time. Stop. Bang. It is a hard starter also, which is ok for mee, but my wife has drawn a bullseye on it.
Anyway, I have done maintenance every year, lube, etc. New friction wheel in last year.
So.... Is there a plug and play more powerful engine that I can bolt on? By bolt on, I mean just that, no drilling, futzing with pullies, etc. Maybe a ohv? I hit the small engine warehouse site, but don't know what I really need.

Thanks!