I might have the world's first 64.9 cc four stroke conversion...Sthil BR550 backpack blower..
24-8 prop-, 6000 rpm, 1200 rpm idle...Weighs about 6 lbs...There are no flat places on the back for the mount, you have to get real creative...Will post some pictures after I get it off the test stand....It's gonna take some tweaking on the carb, I can't get it rich enough without closing the choke partway, but maybe a carb from a Ryobi 4 stroke would work..It comes with a proprietary Zama, 2 needles, but it seems to be way too big...I put a gasket under it with just 2 small 1/4 inch holes in it, and it works without the choke closed..Interesting project...
Captin John will love this one
Only 1 other problem so far, it runs clockwise..Pusher prop needed...[8D]

RCIGN1: Sounds like a fun project so far. Is it possible to use prop on other end of crank? I do not know what this engine looks like...so I am now very curious what you got there!! Take care....its getting hot here in Mich. Capt,n

Hey Captin, no can do...the shaft on the other side had the blower impeller mounted on it and is straight, no taper..also there's no way to put a mount on the other side..It's bad enough the way it is, you'll see when I can take a picture....