I spent the afternoon looking for a Ryobi 31cc (trying to buy locally) and ran across a Bolens weedwacker w/31cc engine. On the i.d. plate was "3MTDS: 0314RA: EM". Anyone know if this is the same as Ryobi? If so, conversion parts are everywhere! Also, does anyone have experience w/a Ryobi 31cc in a 3d plane? I'm looking for good vertical performance, but then, who isn't, eh? I was planning to put one in an Ultra Lite Stik, but I've read that it need 2 oz. of lead in the tail w/a Saito 1.80, which is considerably lighter than the 31cc. The quest continues.....

I'm sure you will find that it is, in fact, a Ryobi but these newer engines have the rear portion of the fan shroud cast directly onto the crankcase rather than being bolted on. Will be a little more cutting.

Most of the 31cc weed whackers sold (under many brand names) are Ryobi's.

Look for the engine to be mounted inverted and with the pull start on the output end.

Enjoy,

Jim

I have a Ryobi 31 with a APC 18x10. it starts easy, runs great and pulls about 11 1/2 lbs on a fish scale at 7000 RPM.
It weighs about 4 1/2 lbs less prop and is on 14 lb 4 oz plane ( total weight less gas) that has no vertical.
Hope this info helps.

Thanks very much, guys. I am agonizing over what aerobatic arf to put one of these in. I am having a hard time finding one that will handle a 4 lb. + engine without adding tail weight or cutting the nose off.

mdavies31, what plane do you have yours in?

I built a 166% sized SPAD DPS (DasPlasStick). Cheap, quick and easy to built with looks only a mother could love.
It is my first gas plane and a knew I would need something tough and easy to repair.
Here is the link the SPASD website. You can find the DPS in the Spad Originals section about half way down the list.
Its a .40 sized 48 inch span plane, I made one, only a taildragger and two aileron servos, like it so much I made a .75 sized 60 inch one and now this 80 inch Ryobi 31 plane. If I was to do it again I would build smaller thus lighter for the Ryobi.

http://www.spadtothebone.com/

Mdavies, have you experiemented with other props to see if they give you more thrust??

Have tried APC 18x10, 18X8, 16x8, Top Flight Power Point 18x10 and a old Dynathurst 18x10.
THe Dynathurst was by far the worst and heavy too, the APC 18x8 was my favorite, had the best air speed but I broke it before I got the scale. Have more ordered, will do more testing when they get here.
Strange thing is the Ryobi turns 7000 rpm with each one, no change in rpm with a prop change.
I think it needs a bigger carb to get more rpm with the smaller props.