...Does anybody know if replacement parts are available or are these throw-aways if they break???
Hmmmmm...... yeah, parts are available... comes with a manual with parts break-down picture and 800-number to call for support and/or parts. But, at $99.oo, why would you spend time, energy and $$$s on repair... anything more than a spark plug, air filter and oil change would cost more than a replacement engine...
...yes a worthwhile motor if you are close to a store that sells them, if not buy 2-3 to cycle through as needed ............if not buy a Honda or Kohler.
I've worn-out both both Honda and Kohler engines... yeah, good engines, but certainly not worth the extra $$$s for the fancy nameplate and paint... and they ain't cheap to repair either.
I've pretty much come to the conclusion that any single cylinder engine, 20 HP or less, made in the last 30-years, is a throw-a-way regardless of who made it... We live in a throw-a-way world... when's the last time you've heard of anyone rebuilding a starter, or alternator, or... when's the last time you've heard of anyone even taking one apart... do you even know anyone who knows how to fix one? Heck, most of the time the parts and labor would cost twice the price of a new one. I can remember when engine overhauls were a common place thing... now-a-days we just short block, or long block everything, it's cheaper. The manufacturers don't even build em' to be overhauled anymore, when they're worn-out, they're junk.