In my experience, those "aluminum welding/brazing" rods rarely work well for anything we might use them for on our engines.  One guy reported he could get fairly passable welds if everything was done absolutely perfectly, but that it was brittle and would crack with very little vibration.  It would be even tougher to try to fill holes with it.  It is sometimes difficult to fill holes even in steel with conventional gas welding or brazing.  It is hard to get the bottom of the hole hot enough, and when you try to feed rod to the bottom of the hole it melts to the sides, filling the hole before you can weld into the very bottom of the hole.

Better to see if you can go the next size up with new holes and threads on that cylinder.

AV8TOR

Twin Star

I am just using the stock Ryobi muffler. It sounds much louder in the video than it does in the air. I had the opportunity to take it out to fly today and it ran silky smooth and didn't so much as hiccup. Not an over abundance in power, but it flew the Rascal very nice. I am very happy with it and for the type of plane the engine is mounted to it will do just fine. I also maidened another Rascal 110 for a buddy today, and his has a SV 26 gasser on it. I would say his SV 26 was probably producing just a wee bit more power than my Ryobi 31, but the Ryobi was running 10X smoother than that SV 26. In fact the Ryobi ran perfect no matter where I set the throttle. It ran just as well at 1/4 1/2 throttle as it did at full.

flyguyeddy

I am a member and past President of the Spoon River Flyers club located in Maquon, Illinois. If you are in the area we always welcome guest to drop in and fly with us so long as you carry AMA. We have a friendly bunch of guys out every weekend who always enjoy a new face to talk to and we welcome all types of model aircraft. We don't care if it runs off rubber bands or a jet engine. If it flys....we enjoy it. 

Twin Star

I have another Ryobi I am currently converting that has the larger bore Warlbro carb. I considered taking the smaller bore Zama carb off the Ryobi in the Rascal and switching it out with the larger bore Warlbro, but as you pointed out....I think the power and RPM's are pretty descent the way it is and perhaps someday I may opt for a better muffler and try another carb, but man it was sure running sweet in the air in its stock form. 

combat

I may have to try some of that alumiweld when I visit Harbor Freight next just for something else to mess with. Thanks for the info.

 I also wanted to mention that yesterday when I was flying the Rascal with the Ryobi....I had a fellow flyer use his point-n-shoot temp gauge to see what kind of head temperature I was at after flying the Plane and what it was reading sitting on the field running after I came into land. He told me he was getting a head reading of around 180 degrees running. So I figure up in the air cruising that my head temp is probably running somewhere in the 140-150 neighborhood. I am thrilled with that and would be curious to know what other folks are getting and what type of oil they are using and at what ratio? I am using Klotz 80% synthetic/ 20% Castor mixed with gasoline 40:1. Of course head temps climb quite a bit right after you shut an engine off...so I would be more interested in what temps folks are getting after flying and with engine running? I really did not know what kind of temps to expect on mine since the Ryobi fits entirely inside the cowl and the only cutout on the cowl is a few air holes drilled behind the spinner and a cutout for the head at the bottom. It appears that it is staying nice and cool, and I am not sure how much credit the Klotz gets or if it is just the nature of these engines to run fairly cool. I was always happy if my Zenoah G38 was running under 220 using Lawnboy Ashless oil mixed 32:1.....so the 180 temp looked nice on the Ryobi running Klotz at 40:1. Of course the G38 was spinning up a fw more RPM's and more then likely has more internal friction due to tighter tollerances, but still I was thrillled.

Those aluminum welds sure look nice.  I'm impressed.  Congrats on the plane too.

AV8TOR

quote:

Those aluminum welds sure look nice.  I'm impressed.  Congrats on the plane too.

AV8TOR

Thanks.   Im not saying its perfect in every application but i do think it does have its uses.  If you get some it does take some practice to get used to it.  try it on some scrap pieces first.  and remeber must be clean.

if it's a walbro carb, go to a local mower or saw shop and ask for a D20WAT, depending on their markup it can range anywhere from $5 to $15, this is the seal kit for the carb, has diaphrams and gaskets for several different versions of the walbro WA and WT carbs, the kit with the meetering lever and needle is K20WAT, generally costs a couple dollars more than the D kit, but also has the diaphrams and gaskets. I ordered like 5 of both online a while ago to have on hand I think I got them for $3 and $5, I can look where I got them from if you want to know, I just did a google search for the part number and found a good place.

I don't know the part number for Zama carbs, I really need to get a few rebuild kits for those on hand...

http://zamacarb.com/pdfs/QuickKit_CR2009.pdf

http://zamacarb.com/pdfs/Distributors2009.pdf

http://zamacarb.com/tipspage.html

A few links that may provide a bit of good info.

quote:

Hello, Ive got a ryobi 31cc weedeater that Im tryin to keep runnin, its acting like the the rubber pump is dried up and not pullin fuel. Was hoping you fellows could point me in the right direction

I forgot to mention, but I am assuming you have the plastic needle limiters off, because you will need to be able to open the needles quite a bit more than the limiters allow. The Ryobi requires alot more fuel draw as an airplane engine then it did as a weedeater, but perhaps you allready knew this. Just wanted to make sure. 

quote:

I can offer you something to try. First make sure the main fuel inlet line comming from the tank is hooked to the inlet that is opposite side of the adjustment screws. Then attatch a 2" line to the brass fuel tube that exits near the adjustment needles. Using a syringe you will hook that to the 2" piece of fuel tubing that exits near the adjustment screws. Pull the syringe out which will draw fuel from the tank and thru the carb and up into the syringe. Now using the syringe you will push just a bit of the fuel back into the carb, but leaving the syringe about half full. Now you should be able to start the engine and keep feeding the engine with the syringe to keep it running. The idea is to get the gas and oil to soften up the diapram and seals until it starts pumping fuel on its own in the event that your carb was just really dry from sittng for an extended period of time. This is also the same method I use to prime my engine since the carb is in a spot that is tough to get to. The primer line works great. I also had to use this method to help keep my engine running when I started my Ryobi the first time as an airplane engine and had to do major adjustments. Just something you may want to try to see if your carb will start to pull its own fuel after you assist it a couple times with the syringe. 

Combat

I wish I could take credit for the idea, but when I was trying to figure out a good way to choke the engine a friend of mind said "Why don't you just use the primer line and prime it with a syringe?" I must say that that was almost to easy and it works like a charm. I just run a short primer line out the top of my cowl with a plug in it. I just pull the plug when I am ready to start it and suck fuel up into the carb with the syringe, open the throttle and push it back down into the carb. I then remove the syringe and replug the line. Works perfect!

Combat

Yea...you don't need a seperate choke. In fact you don't even need to touch the carb. Just pull some fuel up with the syringe thru the primer line...open the carb and inject it right back thru the carb. Close the throttle back to idle and it starts every bit as well as if you had used a hand choke. Just make sure you recap your primer line when you are done priming it. On a few occasions I have had to prime it twice, but normally one time does the trick.

 Thanks for all the great advice so far. Had it runnin good the first couple of cuts then it just started gettin worse,had to adjust the low end on the carb each time. This last time I Couldnt get it to run worth a hoot. The reason I think its the pump is that if I push in on the primer bulb slowly it seems to run much better. Havent stripped the carb apart yet to look inside, will have time tomorrow to tinker with it I plan to pick up a new plug while in town tomorrow the one thats in it now looks clean to me but you never know. What would air in the lines indicate, havent looked for that yet. Almost thinking of going to the big bore carb just for grins, would it work while still on the weedwacker? Thanks for all the help so far, this forum is one awesome tool.