[JRTJH]

Briggs and Stratton is probably the largest supplier of small engines for the US market. They build "state of the art fuel injected engines with pressurized, filtered lubrication systems and they build "rock age, oil slinger engines with a rudimentary carburetor.

One will last "indefinitely" and one will "make it through a couple of years of average service". One is found on $2500 lawn tractors and one is found on $600 lawn tractors. Both have a B&S sticker on the engine cowl.

It's the same with Honda engines and with Yamaha engines, just like it is with almost any other "name brand knockoff".

China has, in the past 5-10 years, produced "reverse engineered Honda engines" for nearly every market, some of which are junk and some of which are actually "great copies of the original" and parallel them for quality/service.

The "key" (at least to me) is trying to determine if the "Yamaha engine in a COSTCO generator" is one of the "high quality Yamaha engines with state of the art technology" or if it's an "old version Yamaha" that doesn't have the same quality/service expectation as the "Yamaha engines that are in Yamaha generators"....

I've got a Billy Goat walk behind brush cutter with a 13HP Honda engine. It's over 20 years old and still runs just like it did when I bought it in 1996 or 97. They still sell that model with the same engine for around $3500. They have the same "size brush cutter" for $1199 with a 9HP B&S engine. So, just having "the name on the outside" IMHO, doesn't mean as much as it used to mean.....

I'm not suggesting that a COSTCO product with a Yamaha branded engine is not a Yamaha engine... I'm suggesting that a COSTCO product with a Yamaha "brand" engine may not provide the "identical quality/service capability" as a Yamaha engine in a Yamaha generator produced under the Yamaha brand. When you consider "the rest of the generator" from the electronics to the generator/alternator head, there's much more that can "go wrong" even with a name brand engine powering the inferior to OEM parts.