I'm 90% sure they are 40:1. A good two stroke saw oil such as Echo or a synthetic is as important as the ratio. Some tout the benefits of AMsoil. If the thing is newer than 15 years old I doubt it would be any richer in mix.

Robar: Use the old tried and proven method . Utilize your Engine Oil Dip Stick . As Bill has advised 20 oz. is normal but once your crankcase has been drained add 10 oz and check level with dip stick and only fill to just under full . Better a little low than over filled which will be deposited within you air filter and cause carbon deposits and worse .

I don't know their reasoning, but it may have been to align that part with common oil filters in Japan. Honda motorcycles and other Japanese makes of motorcycles use a metal can with a replaceable filter element. That type has been used for at least since 1970 on 'cycles. Both types filter well. The cartridge type is messier to change, but has the advantage of providing a look inside the filter can to get a view of what has been collecting. I prefer the metal can over a plastic one. In Japan, a number of engine design features were first tried on motorcycle engines before transferring to automotive engines. For example, 4 valves per cylinder first appeared in a motorcycle enigne. Yahama went as far to make a 5 valve cylinder and then settled on 4 valves. The problem of designing machinery to actuate multivalve per cylinder engines was worked out on a motorcycle engine.

different paint color, louvers horizontal on Trane and vertical on Am Std. Fancy black top. All that matters is the same.