so, am I correct to assume that something like the above certification would be on a generator's engine?With a few exceptions, nearly all small gas engines are required to have EPA emissions certification to be legally sold in the USA. Models sold in California must also pass California Air Resources Board (CARB) certification too.
The certifications are for the engine in "as tested" conditions. Modifications to the engine, including conversion to natural gas or propane, rigging external fuel tanks, adjusting the mixture screw, etc. are considered tampering and against EPA and CARB rules.
A certified engine will have an EPA sticker; here's a sample:
Yes. You should find a similar sticker on pretty much any small gas engine (generator, lawn mower, tiller, snowblower, etc.) sold new in the USA.so, am I correct to assume that something like the above certification would be on a generator's engine?