Why jump from Ryobi to Stihl. They all have the same crappy carb and fuel line problems. Anyway those fuel lines can be cracked and cause your leaks. A diaphragm kit and or primer bulb takes a few minutes to install. Call around or go around to dealers in your area. Bet you'll find a bulb, diaphragm kit, and new hose. Good luck. Been there and done that. In fact that's about all that ever breaks on these things. Take the carb and pieces of fuel line with you. A new in-tank filter would help too.

I can't tell my the model number if it's two stroke or 4 stroke? two strokes usually have zama carb. which you can get kits for if you find the numbers stamped in the carb. housing. newer 4 strokes may have the barrel type carb. I think zama makes them, you maybe able to find a carb. kit which should stop the leak providing it not the primmer button, fuel lines or gas tank. 4 stroke gas tanks are molded in two halfs and where they are glued togather they spring leaks. I got two four strokes and over the years both tanks have leaked below the filler neck at the split line.

Many thanks for the quick responses gents. To rc: yes, it is a 2-stroke. Also, rdaystrom suggested I ck out the local dealers/repair shops and, sure enough, I found a guy in McKinney, TX (near here) who sells parts but said I needed to bring the carb in so he could read the numbers and he might possibly have a kit for it...... and could probably sell me some fuel lines and a new (tank) fuel filter too. The lines feel soft and pliable, but if he has them or just bulk tubing, I will go ahead and replace them (based on what I have read in this forum + other Newgroups.) From what I read at the ZAMA site online, my ZAMA carb is used on all the so-called "Simple Start" models and this RYOBI is called a "Start Plus" (but it says "SS 30" in big letters on the housing so I'd wager it means "Simple Start 30cc.) I'll see the parts guy tomorrow and post back on the final outcome.

Just wanted to follow up on the fuel-leaking Ryobi string trimmer. I went to a couple of mower shops and they were unable to get me a carb kit......both of them said that their distributor feels that some manufacturers are sort of cutting the independent shops out of the parts loop for many items. Be that true or not, no carb kit; so I ordered a new carb online from Gardner, Inc. It was back-ordered for several weeks, but as soon as it came in they charged my CC and sent the carb ($45 + shipping). I installed it and the leak problem is gone...the trimmer now stays *dry* between uses. It does run a bit lean on colder days (as it always has) and the shops told me that what I call the *Ralph Naderized* carb can only be adjusted with a special tool...and neither shop had one! I cut a screwdriver slot (with my thin Dremel cutoff wheel) in the old carb just to see if that would work and it can now be adjusted just fine. I have included a link (which I hope will work) if you want to view an image of the mod. No big deal though, as I'll bet most of you have done that to remove a twisted off machine screw many times in the past. My Ryobi really screams in the heat of summer, but when it is cool, it sounds as if it is trying to 4-cycle at higher revs and I believe it is due to running lean, what with with the cooler air and moocho oxygen. I will cut a screwdriver slot(s) in my new carb when it thaws out around here and, I hope, be a happy camper.
http://www.flickr.com/photos/83478093@N00/?saved=1

All of my fuel lines went bad and were cracked, broke and or leaking, but not unitl after about 10 years. Replaced all fuel lines today and now have the fuel leaking out of the carb. so it must be the diaphragm. I could see the fuel from the primer bulb moving to the carb. I will try to find a diaphragm around if possible. Has been a good running string trimer and starts easily. Don't want to buy another if I don't have to.

IMO probably not the diaphram but rather the needle sticking. I would try to clean the needle and seat using carb. cleaner. to get to that you will see if you diaphramn is still serviceable

I have a Ryobi R700 or 700R, any way the fuel line out of the fuel tank cracked & was leaking. I purchase 12" of fuel one & replaced the line from the bulb to the carb & the line from the tank to the bulb. Now when I run the engine & high RPM's the line from the tank to the bulb pops out of the tank & the tank starts leaking. The engine runs great till the gas in the carb is gone.

From what I gather you just push the fuel line into the hole in the bottom of the fuel tank, there is no fitting or insert for this hole. You just push the fuel line into the hole.

Is there something I'm missing or is there something else I need to purchase?

I have the exact same problem after replacing old cracking and hard fuel line. The hose just sticks into the tank and winds-up leaking like a month old depends.