I have the same instruction sheet that came with my Merco 49 Black Streak although mine's printed in black and gives the manufacturer as D. J. Allen Engineering. The interesting part under the Fuel heading is that a couple of times there's a warning not to use medicinal castor but a castor such as Castrol M (which is widely available here in Australia ). Apart from the Black Streak I've also got a brand new Series 2 (twin plug) 61 and what's thought be the very first 49 ever sold in London, ordered the day before they were to be delivered to hobby shops and picked up the following morning. This was given to me by the original owner (an extremely nice guy from Tennessee) and although he'd used it for many years it's got the best compression I've ever felt with a ringed engine. And it started on the first flick .