I would like to add that if you needle valve diapram is not soft and is stiff and hard then it will not open the needle valve properly and at the right time and this could also strarve it for fuel. pushing the primer bulb would still work if this was the case as it pulls fuel into the fuel bowl after the needle valve. It is also very important that the diapram and the gasket go to the right place or it will change how it activates the needle valve. You could also have a piece of junk in it somewhere clogging up the works. if the diapram and the fuel pump seen pretty supple than this is probably the case and just needs a good cleaning.

Got the new plug and figured what the heck went ahead and cleaned the carb up,was surprised there was some gunk inside but nothing major. The diaphram looked stiff and I beleave it needs to be replaced, it ran but still haven trouble keepin it in the sweet spot it almost seems like its jumping out of adjustment on its own.

If you even slighly think the diaphragm is stiff, that is probably your problem.  They need to be "floppy supple" to work properly.</p>

AV8TOR</p>

<p style="MARGIN: 0in 0in 10pt" class="MsoNormal"><span style="FONT-SIZE: 9pt; LINE-HEIGHT: 115%; FONT-FAMILY: "Arial","sans-serif"">Hi. I have just pulled a Ryobi from a trimmer. It saw a couple of light seasons <span style="mso-spacerun: yes"> </span>on it. I removed all the excess off of it including mag. I intend to use <span style="mso-spacerun: yes"> </span>XYZ EI from hobbycity. Also replacing the Zama carb with a 12 mm Walbro. The cylinder bore is very clean, no scratches or ridges.

</p></span></p><p style="MARGIN: 0in 0in 10pt" class="MsoNormal"><span style="FONT-SIZE: 9pt; LINE-HEIGHT: 115%; FONT-FAMILY: "Arial","sans-serif"">I have cut all the excess from the back cover.

</p></span></p><p style="MARGIN: 0in 0in 10pt" class="MsoNormal"><span style="FONT-SIZE: 9pt; LINE-HEIGHT: 115%; FONT-FAMILY: "Arial","sans-serif"">Starting to draw up plans for biplane that will be just a little bigger than my Kadet Senior. 80 inch top wing 70 inch bottom 13 inch chord, for 1950 square inches. I am will be using boost tabs <font color="#800080">http://www.rcuniverse.com/forum/tm.asp?m=375915</font> <span style="mso-spacerun: yes"> </span>to cut weight <span style="mso-spacerun: yes"> </span>i.e. normal servos (48 ounce inch) and 1000 ma battery. That will cut a about pound versus using 1/5 scale size.</span></p><p style="MARGIN: 0in 0in 10pt" class="MsoNormal"><span style="FONT-SIZE: 9pt; LINE-HEIGHT: 115%; FONT-FAMILY: "Arial","sans-serif"">My question is does anyone have a drawing of a mount plate they could share. I have some quarter inch aluminum plate I will cut mine from. My plan is to use aluminum stand offs drilled and tapped for quarter twenty bolts to mount to the firewall with.

</p></span></p>

Sounds like a fun project. Sorry i dont have a drawing for the plate. i just drew mine out myself and cut it out of a square pice of 3/16" aluminum plate. i cut out the center with a hole saw. I dont have the dimensions but i can get them tommorow maybee.

On the XYZignition. Mine failed this weekend causing a very frustating weekend. if you do go with the xyz or any electronic ignition for that matter I would keep all your stock parts and keep them with you as aback upjust in case your electronic decides to poop out at a flying event. I wish i had mine with me i would have taken all the sensor parts off left the battery and ignition box in and wired the plug lead out of the way, installed stock ignition and kept on a flying. Honestly you really dont need the electronic and there really isnt much advantage to it. I dont think im gona bother replacing mine.

Oh yea i think mine failed cause it got gas soaked from a fuel leak in the fuel line.

Thanks <font size="2" color="#00265e">combatpilot</font> . Then would the Rcexl unit be the one to get? It is less than 10$ more.
I will start cutting my plate tomorrow.
On the plastic back cover 3 holes for the cover screwa are raised and 1 is flush on my motor. Would trueing the cover in a lathe be a good ideal. I have a 7 10 lathe.

I dont think it needs to be that technical. i trued mine on a belt sander. it wouldnt hurt though. kind of hard to chuck up as the backplate is kind of tapered.

Honestly I really dont know. I do like how the rcexl has a metal case instead of the plastic one the xyz has. the palstic case on mine came apart and i had to glue it all back together. It has two screw mounting holes and i think the engine vibration killed it in about 20 min of flight time. that coupled with the gas soaking was the demise of mine. I think any one you get i would wrap it in foam and let it free float to reduce vibration. for the 10 bucks more does it come with the sensor also?

I really dont know which one is better. What i can tell you the reason i purchased mine was to see if there was some power to be gained by not having the rotational wieght of the flywheel and if the stock magneto magnetic drag had any affect on power. I found that there was absolutly no gain to be had as far as power out put. a stock mag would produce just as much as the electronic. the only advantage i found is it had a better idle quality and was much easier to start. other than that i think it overcomplicates things with another battery, sensor and a ignition that has to be timmed and on and on. I am not going to use this and will stick with the stock ignition as it produces just as much power and in my opinion and this is just my opinion is far more reliable than the electronic ignition as there is just far less to go wrong. the weight savings just isnt enough to be a concern. granted you are losing the flywheel and coil but you must add back in the box and all the works ie sensor, and a fairly large battery. so the weight savings really isnt much

the other advantage of the RC Exl is that you can move the weight around instead of it all being at the nose of the engine which helps for sport planes, but warbirds seem to need the nose weight anyway... the weight savings isn't all what everyone thinks, it only ends up being an ounce or two...<div>
</div><div>so, if it starts easy and you don't need to move the COG back on the plane, don't bother... on my mac 32 that I just put the RC Exl ignition on it starts nice, should run better once the ring breaks in.</div>

I had the same problem with an XYZ ignition on my Ryobi.  I switched to RCeXl.  Both are the same price at southeastrcengines.com
I had my XYZ ignition screwed down to a plywood plate and the bottome cover broke off from the vibration. 

Buying from southeastrcengines.com gives you a warranty in the US.  I prefer the easier starting on my Ryobi.

Jim

Then i will buy mine from southeastrcengines.com.That is when I get some spare change. Started making my mount plate. Will try to scan it as a pdf and post.

I use a single cell 1800 mah LiPoly battery to power my CHXL (essentially an RCEXL) ignition. It weighs a fraction of the weight of a NIXX battery and it runs fine at the lower voltage. Check out the CH ignition web site for tests that Bill has done on ignition function vs. supply battery voltage.


Except in rare occasions you can't hand start an engine with stock ignition.

I got a chance to fly my plane with the ryobi again today after i put the stock ignition back on. it didnt add back much weight but the thing i didnt figure in was the weight was moved furtuther out to the nose so now it is nose heavy. I may have to go back with a electronic again for the weight distribution.

Also my carb was so worn out from all the testing that i decided to go ahead and and install one of the wt577s i got on ebay. while convering itI noticed this carb actually has an acellerator pump that is run off of the throttle shaft. this carb lends itself well to conversion and runs great

Jack are you sugesting that maybee my battery voltage was not adequate? I had wondered that myself and checked my battery several times and the voltage was 5.95-5.97 every time i checked. I am using a 1800 mah nicad battery

[quote]ORIGINAL: diceco



I use a single cell 1800 mah LiPoly battery to power my CHXL (essentially an RCEXL) ignition. It weighs a fraction of the weight of a NIXX battery and it runs fine at the lower voltage. Check out the CH ignition web site for tests that Bill has done on ignition function vs. supply battery voltage.


Except in rare occasions you can't hand start an engine with stock ignition.



[/quote ]Where do you buy the 1800 mah battery &amp; what brand are they? Thanks Capt,n

Im not sure where it came from. I bought it second hand from a friend of mine. he gets his somewhere online. i cant remeber the name of it but i know its not cheapbatterypacks.com

I will ask him next time i talk to him.

Jack i just realized what you were talking about. you are using a single cell lipo and thats whay you reffered to the lower voltage. duh sometimes i suprise myself lol.

Wow, I just got through spending about four hours reading this whole thread. I have been a little bit curious about this whole conversion thing for the last few years and now I can blame you guys for getting me started. I have a couple of old weedeaters in my shop that I will be stripping soon to try to determine what i have, engine make wise. I will be doing a Ryobi for sure though. I figured a small engine shop would sell the old engines for junk but I will call around to see if I can round me up some conversion canidates if mine are'nt Ryobis. Thanks much for the education and I will keep following this thread to learn what I can.

Bill

The ryobi that I have came out of a Troy Bilt TB70SS weed eater. It has the four transfer ports and also has two rings. I just wanted to post this so maybe when yard selling or scronging, a person would know that this trimmer has the desired engine.

I also posted this just hoping that maybe somebody would chime in and revive this thread. I have read it almost two times and have learned so much from it. There was some childish posts made but they are easy enough to ignore. Anyway, thanks for the vast majority of the posts from the majority of the posters for a gold mine of information.

Bill

Hi, My name is Larry. I have a machine shop and just started working on a Ryobi 31 CC weed eater motor. Mine has a 1.375 Diameter Piston and a single ring. I actually ran it today with the CDI Ignition and the results where encouraging. I had to open the LS NV 3 turns b4 it would run. I could hand start it with a 18-6 Dynathrust prop.
I have tried opening the pictures that you have uploaded but can't seem to get them to open. Whats the trick?
Thanks,
Larry
[email protected]

This needs a web site all to the conversion of RYOBI's.From what I am getting it's a good engine and converts easy enough.But a web site would make things easier to understand .Just my thoughts.

CraigjP in DFW ,Texas

Craig

Its a great engine foe the right plane. They run good, but the downfall is there weight. I have a Ryobi 31 in a big Rascal 110 and that plane handles the extra weight great. However the rule of thumb is to use them in a Plane with at least 1000 sq in of wing area and the Plane should probably weigh in 12lbs or under with engine installed to have good performance. For scale flight you can get by with a little heavier plane. Big Cub like planes and other scale machines are suited best to this engine. Mine runs flawless and I also have another one waitng to go into another project. There are some websites out there like Jag engines and some others that detail the process of converting.

Do you have a link to jag engines?

CraigP
DFW

http://www.jagengines.com/2instructs.htm

Let me add this.I have  a Ryobi on hand so thats what I'd be using.Using it for what kind of aircraft? A video/camera plane[read drone] that is more capable than an electric sailplane.So a larger aircraft is a plus.

CraigP

Craig

Something like a big Hobby Lobby Telemaster, Sig Rascal 110, perhaps a large stick plane like the Great Planes Giant Stick ARF, any 1/4 scale cub should handle the weight or perhaps something like a Four Star 120. There are plenty of options. However a little surgery may be required to the firewall of any of these planes to avoid adding a bunch of tail weight. Nothing to difficult.

I will have to checck those out,someday soon.To be honest in my mind I am laening toward PVC pipe and blue foam wings,again the blue foam is on hand.
Well off to work to pay for this !

CraigP