"Is it economical or feasible to properly rebuild a 7 HP Tecumseh engine on a snowblower? Compression seems fine. Has been burning oil to some degree for the last 3yrs, but this year its' burning a lot - maybe 1/2 pint oil for each gal of gas. Until last year, was using 5W30. This year, switched to straight SAE30. I could get a new Tecumseh SnoKing engine for about $350 including shipping."
(From: Mother (firstname.lastname@example.org).)
As a finalist in the All-American Engine Repair Championships formerly held at the Outdoor Power Equipment EXPO (an industry trade show) in the Tecumseh division, and as a Briggs and Stratton Master Service Technician, it has been my experience that:
If this engine is on a top of the line product, such as Ariens, Snapper, or BearCat, it is probably worth repairing, as a new comparable product is big bucks (and overpriced).
If this engine is on a mid-range product, such as Toro, Simplicity, John Deere, Husqvarna (European product, not USA built), etc., then repair is probably still a good option, due to the overpricing of similar replacement products.
If it is on a Murray, Noma, AMF, Dynamark, Ultra, Sears, MTD, YardMan, White, Husqvarna (USA built by Murray/Noma), or other discount store brand, go buy a new machine. The cost of a new unit is not much more than the cost of the engine repairs, and then you won't have a worn out piece of discount store equipment to break down again in three weeks when something else goes bad...