Yes, but that "not running right" is just the engine and not the result of bolting on a larger heavier blade, and using it daily to mow the city park with a fouled plug and bad gas. Not to mention the irony of you not making your own case. You've pointed out the ineptitude of Joe Homeowner who like a lot of folks that work on their rigs, should instead limit his mechanical endeavors to keeping the wheels on his kid's tricycles from falling off.When I worked on lawn mowers one of the things I'd hear is "it wasn't running right so I replaced this or that and now it won't run at all, must be something else."
Every time I heard that I checked whatever they "fixed" and it was almost always the issue.