I just got my stock ryobi carb working this evening. About 6 months ago I converted it using a jag setup and was getting 6700rpm with a zinger 18x8. Which is about right. After sitting for the 6 months I installed it on the plane I built for it and it ran like crap. Would only get 5000rpm and had to lean out both needles a lot which wasnt right. That was using 6 month old gas. I made up some fresh gas and used klotz oil and got nothing, wouldnt start. I put in a carb kit, same thing. So I disassemble the carb and cleaned it in a sonic bath for 45min using water and dawn dish soap. During assembly, I adjusted the float valve also. Runs like a top now. Got back to 6700rpm. This is my baseline. The stock carb also has the primer tube on it. I blocked that off with some med tygon with a fuel dot and zip tied it. I had some surging at one point and I think it was leaking a little there. I also found a small cut at my fill line. Basically, a bunch of little things added up to make it run poorly. Tomarrow is the maiden flight of my highly modified Bandito Grande. Had to move the firewall back 3 1/4" to get it to balance with no additional led. Total weight is 13 lbs 14 1/2 ozs.
Edwin