I think those "commercial" motors don't have the Oil Injection and I think they had a different cylinder head which allowed them to run on low octane fuel. That's what makes them so Tough
Yamaha commerical motors "C" didn't have oil injection either . . . at least back them.
Commercial is just a marketing gimic . . . so they could sell the motors w/o a standard warranty, w/o oil injection, and with a Tough Paint Job
