That mower is a good buy and should serve you well. Tecumseh sold to a company that promised to keep the parts side going and many are available through the aftermarket.

Any Toro owners with the Tecumseh engines out there?

In this case I'd snatch it up...though I used to hear the same 'built to our specs' story in Sears and typically take that with a grain of salt, its a good mower and I believe a good engine at half price. Does sit have a warranty?

Have a Tecumseh 195 (same as the one you're looking at) on a Lawn-Boy 10684 and it's been great since 2004. You must use Sta-Bil in your gas can every time you fill it to keep the main jet clean, but even if you don't, it's easy to take out and clean - it's the brass bolt that holds the fuel bowl on the carb. Very powerful and dependable engine. Figure on using SAE30HD oil in it which is good down to 32F. I'm extravagant with my mower oil and use Opti-4 30W in it and Royal Purple 10W30 motorcycle oil in my Honda commercial engine. I change oil once a year and basically throw away oil that still looks good enough to put back in.

I had that setup for 4-5 years to mow ~1/2 acre and had absolutely no engine or carb issues (sold it and it still ran like knew). Great engine in my opinion and I would not worry about prepurchasing repair parts that likely will never be needed. I don't even need a mower and I would pick that one up in a heartbeat if I saw it.

The Tecumseh is a fine engine that will last a long time. You might consider worrying more about whether the mower will do what you want, whether the controls are appropriate and work satisfactorily, etc.

The engine will be the last component to fail on most mowers, yet many guys obsess over them to the exclusion of more important parts. Wheel adjusters, engine and drivetrain controls, wheels, etc., will wear and fail well before the motor.