We've had our Craftsman snowblower for four years if I remember correctly. Today was the first day we've had any problems with it and that was due to the fuel stabilizer I used back in early spring. I just couldn't get it to turn over with the pull start, had to use the electric start and after all the old fuel burned out, it started from a single pull just fine like always. I've never really done anything special to it over the years. Change the oil when we put it up for storage in the spring and then change it again in late fall before putting it into use in winter, check the spark plug to make sure it's clean and properly gapped, check all the gears and "driveshaft" and oil the exposed bare metal parts to cut down on rusting. That's pretty much been it and it's been bulletproof.
Actually I take that back, we had one other problem. There was a crossbar between the auger and drive control lever handles that was held on with some press fit cap ends that fell out, probably due to vibrations. I replaced the crossbar with a threaded rod and lock nuts on either side and it's been fine since. And, if it matters any the engine it has is Tecumseh made.