I have a 40cc echo chainsaw engine, I think it is differant from the blower engines, this engine is a Koritz. It will turn a 20-10 at 7000, and it turned the 18-10 at 7800 before I advanced the ignition timing. I have heard from the lawn repair person that I know that the blower engines are high tourqe low rpm engines compaired to the chainsaw engines. STeve