Twin-Ring Ryobi Bench Test Results
 

I just completed the first run of my converted Ryobi twin-ring trimmer engine. Results follow:

1) Despite someone else posting that their twin-ring Ryobi would hand start, there was no way, no how mine would flip start by hand -- either hot or cold.

2) I installed the primer bulb, but not the choke. One website I went to said that the choke was unnecessary if you use an electric starter. I found cold starts to take QUITE a bit of electric starter spin before firing, even with lots of primer pushing. I think I'll put the choke back on! Warm starts were instantaneous with my standard Sullivan starter.

Question: Does the primer bulb actually inject any fuel into the carb bore, or does it just get the carb's diapragm flow paths to and from the tank bled-in?

3) With less than 12 ounces of 32:1 lawnboy oil mix run thru it so far, I'm getting a solid 7000 RPM with a Zinger 18-6, stock Zama carb, and the stock muffler.

4) I really like the quality of the Paragon Engineering conversion components I chose. I'm a very happy camper with their quality & quick delivery!

Other pics follow in next posts...

Ryobi Pic
 

pic attached

Twin-Ring Ryobi Bench Test Results
 

The primer bulb only fills the carb...

Twin-Ring Ryobi Bench Test Results
 

Volture;

I have a Ryobi, might be the one you are referring to. One or two flips and she starts every time. I was given a few pointers in starting these gassers. If you have access to your carb, stick your thumb or finger to block off the opening, make sure the ignition switch is OFF, and rock the prop back and forth at tdc. till you see some gas on the end of your finger, then give her a good flip. It might help.

Good Improvements!
 

These newer two ring ryobis seem to have great potential!

Those seem like very respectable numbers to me, for a 31cc and with the stock muffler to boot!!

What's the weight on the converted motor with muffler?

Time to get to work on mine!! Finishing up a Poulan 42cc conversion right now. Ryobi is on its way to me in the mail.

By the way, what plane are you planning for this motor?


High Flights!!
CrazyHerb

Ryobi Conversion
 

CrazyHerb:

Weight as shown in pic (with stock muffler, prop, and aluminum spinner) is 4lb 10 oz. I plan to put the engine on my new Ultra Stick 120, but I think I'll fly it first with my G23. The final home will be either a Bridi Big Bee or Dynaflite Fly Baby -- if I ever get around to building them instead of messing with engines...

- Craig

Ryobi 31
 

I just started flying my Ryobi conversion a couple of weeks ago. I started with the magneto ignition and changed to electronic after I figured out how the engine was doing.

My engine is also a twin ringed engine. I was getting nearly 8000 rpm with an 18x6 prop. I went to an 18x10 and get 6800-6900 rpm, which is a good place to be on the torque curve for this engine.

I closed off the bubble primer port and use the choke. It will not fire until it's been spun with the choke on. Once it fires, I turn the choke off and it starts right up at that point.

The engine is on a SA Super Decathlon that I shorted by 1.75" because it just looked too long. There is more info about this on the ARF forum.

Twin-Ring Ryobi Bench Test Results
 

Rascal329:

Did you do any other mods to the engine other than the ignition? What muffler/carb are you using?

Thanks

Twin-Ring Ryobi Bench Test Results
 

It's pretty much stock. It has a Paragon aluminum twin stack muffler on it. The carb is stock Zama. I now have the C & H ignition on it.

Twin-Ring Ryobi Bench Test Results
 

Hmmm..I thought the twin ring would turn an 18x6 a little better than that. I'm running a stock Ryobi(old single ring) with a paragon muffler and get 7100-7150 consistently with the 18x6. That's with either the MAS classic or a Top Flite powerpoint. I typically run an 18x10 APC on it to keep 4 stroking to a minimum. I get about 6400-6500 on that prop. Hauls my ugly 14 pounder around just fine. I agree, the Paragon kits are top notch. The only thing I don't like with the Zama carb is transition from low to high throttle is rather abrupt...but hey..it's a flyin' weed whacker ! :p

Twin-Ring Ryobi Bench Test Results
 

Does anyone know how I can find Paragon Engineering that make conversion kits?

Twin-Ring Ryobi Bench Test Results
 

Here they are....
http://www.paragonaero.com/ryobi.htm

Ryobi 2-ring
 

Have any of you tried a 20 x 8 prop on your Ryobi? I'm getting 6700 to 6800 (static) with an 18 x 8 Top Flite wood or MA Classic but wondered what rpm might be had with a 20-incher.

I'm also using the Paragon conversion parts except I run a Jag aluminum muffler (all first class stuff). Still on magneto. Everyone that suggested using the primer bulb to help starting gets my vote. If I put the choke on the partial detent (engine cold), pump the primer until I feel a little moisture in the carb, and then apply starter (standard Hobbico), it starts in about 3-5 seconds. Flip choke off after about 10-20 seconds of run time. If engine is warm and has not been run out of fuel, no choke and no prime. If run out of fuel and warm, a little prime is needed.

RE: Twin-Ring Ryobi Bench Test Results
 

Hey

RE: Twin-Ring Ryobi Bench Test Results
 

Try an APC 18x6W and you'll get the most rpm's out of the Ryobi!!!

RE: Twin-Ring Ryobi Bench Test Results
 

Aero this topic is 4 years old

RE: Twin-Ring Ryobi Bench Test Results
 

thanks cdale03:eek: I didn't see the date on it but it was right up we the treads in the forum.