Has anyone tried mounting a 31cc Ryobi, by using the two, 1/4", cylinder to crankcase bolts. I've made a couple of backplate mounts, but I think it might be easier to rail mount it. Any ideas? When I get time to make one, I'll post the pics.

Nashcat

I don't know, seems kinda dicey to me. Looks like there's a lot more beef to bolt to on the backplate.

On the other hand, who knows? Maybe you're on to the next great innovation. Try it and let us know!

Before there was Ryobi, there was the EVRA 190...Same engine with beam mounts cast into the case, came from Hobby Lobby with an aluminum mount....Coould not be hand started, came with a rope and pulley for a starter...
They also sold a gas powered 1/2" drill and small circular saw using the same engine, which became the Ryobi...The rest is history....

As soon as I find a piece of aluminum, and some time on a band saw, I'm going to try one. I'm thinking about using a piece of 3" or 4" angle stock. It shouldn't take over about 5 minutes to make on a band saw. Oh, by the way, I'm a toolmaker.

Nashcat

YES IT WILL WORK I HAVE ONE MOUNTED ON A BIPLANE IT WORKS GREAT THE ONLY THING IS IT IS TOUGH TO GET THE THRUST LINE CENTERED USING THIS METHOD BECAUSE OF THE LOCATION OF THE SCREWS ALL I DID WAS:
TRIM THE BACKPLATE RIGHT DOWN TO THE SIZE OF THE CASE ( SO THE BRACKETS WOULD FIT FLUSH

NOTCH THE BRACKETS SO THEY WOULD SLIDE INTO THE MOTOR A LITTLE BIT THERE IS A LITTLE HUMP IN THE CASTING YOU NEED TO GET AROUND AND POPPED SOME 1/4 IN LONGER BOLTS IN IT BUT FOR ME IT WORKED OUT GREAT I HAVE RAN THE ENGINE A BUNCH BUT HAVE NOT GOT THE PLANE OFF THE GROUND YET I AM DEALING WITH SOME WEIGHT ISSUES I TRIED TO FLY WITH A 15\6 PROP SPINNING 5,600 RPM ON A 18 LB PLANE AND IT WOULD NOT LIFT IT SO I AM IN THE PROCESS OF MODIFYING THE EXHAUST TO TRY TO PULL SOME MORE RPM ALSO TRYING TO TRIM SOME WEIGHT GOOD LUCK !!!!

I tried mounting the Ryobi by the cylinder bolts using 2 "ears" welded to 1/2" square steel tubes running alonside the engine in my Dornier. It had a lot of "pitching flex" meaning that the cylinder could rock back and forth, especially when starting. My solution was a gusset under the front bearing tied into the bottom screw hole meant for the fan shroud. That helped but I won't do another beam mount on the Ryobi