I finally started my 31cc Ryobi converted to EI today. I got the CH ignitions prop adapter with clamp-on pickup. I decided to use S/S ignition and a Zama C1Q-33MD carb. I made a flat aluminum plate mount and standoffs to mount the engine. I just ran it a few minutes to see if it would run. I need to get a different prop and a muffler for it before I fine tune it. I ran pretty good. The weight so far is 3# without a muffler. The weight includes ignition module and flat plate but no standoffs. I can shave a few ounces off by reducing the size of the flat aluminum plate and removing the mounting tabs for the magneto.
Looks like I won't need the flywheel and mag. for the engine. I anyone is interested in the flywheel and the magneto, just send me a PM and we can work out a price. I did have the fins on the flywheel milled down. The engine is a short shaft with 1/8" key.

The long shaft is more interesting.
With EI, manual flip starting is a piece of cake.
Keep idle rpm up, or the engine will cut out suddenly now and then without any cause.

The Ryobi is a darling to convert, see my web pages for all of the work I did. Nice small footprint, and a challenge to tune for more power, staying withing the stamped sheet conrod limitations

Ran the thing again today. Darn thing wouldn't idle down but it sure starts easy. The lowest I could get it to go was 3800 RPM. I took the Zama carb off and found the throttle butterfly screw was loose and the butterfly was moving around. I tried to get the butterfly in the correct position but the thing still wouldn't idle down. I did get the idle lower but not low enough. I can't seem to get the butterfly in the correct position. It's not perfectly round and moves when the screw is tightened. I'm junking the crap Zama carb and getting a Walbro WT-324. It should run and idle better. The Zama was a pain on a Brillelli 46 that's why it was removed and a Walbro was installed. I could never get the Zama to stay adjusted. The high and low would need adjusted every couple flights.
I ran a Zinger 16X8 prop and man the thing would wind up but the top end seemed to need adjusted just like on the Brillelli 46. Anyway, I can't wait to get the Walbro carb on it and get it dialed in.
I'm considering putting it on a 106" J-3 Cub if I can get it to run great.

Just make sure the Carb. doesn't have a hole in the butterfly

What's a good source for WT324? Pricey?

I have a Ryobi 28 and 2 31's. One day noticed oil[X(] leaking from a 31 c.case cover. Everything was tight gasket and surfaces seemed perfect but I thought if oil leaked out gases could leak in/out. Cleaned areas thoroughly-sprayed windex around gasketed assembleys and cranked with ign off. Looked like an old Lawrence Welk show so replaced gaskets with black gasket maker. Neither one has cut out since and all idle at 1100 RPM with WT391, 18X6 prop. Going to your site now. I live for news on modding these (my sense is a better reed valve would mean 1000 rpm or more.) Have you ever actually broken a rod?

I got a WT-324 on fleabay for around $10. I haven't put in on yet. I'm waiting on a throttle shaft from Ralph Cunningham so I can add a throttle arm on. He's sending me one that sticks out farther past the body like on the WT-76 carbs. I can say that Ralph is a great guy. I let you know how it runs when I get the WT-324 carb on it.