How do I adjust carb on a ryobi weedeater - Ryobi Factory-Reconditioned 30cc 18" Gas Hedge Trimmer ZRRY30550

First, mix some really fresh fuel...Ryobi recommends a mixture of 50;1 or 2.6 oz of oil to 1 gal of gas. empty your tank and while it is empty check the fuel cap on the tank to make sure the vent in the cap is not clogged, if it is it will cause a vacuum to be created in the tank and it will not allow fuel to go to the carb. Check the filter on the intake hose inside the tank to be sure it is not clogged ( I replace this filter once a year whether it needs it or not...just a good maintenance practice, they're cheap and I buy them three or four at a time...available at any small engine shop) check fuel lines and be sure they are open.( I disconnect both lines from the carb and blow a little compressed air through them, be sure you reconnect them correctly or do them one at a time). Refill tank with the FRESH gas...Try to start your machine....prime the bulb 7 or 8 times and place choke in start position...pull start handle at least 6 times... if the machine doesn't start...pull out the plug and see if you are getting fuel to the cylinder...if plug is wet you are getting fuel...if it is dry or gummy you are not getting fuel (i'll talk about this later)...then clean plug and plug it back into the plug wire...lay plug against cylinder head and pull start handle to see if you are getting spark...it should show a blue spark at the electrode of the plug...if you have spark you know that the magneto is good...if not you have a problem in the electrical circuit...OK, assuming you have spark and fuel...you may have too much or too little fuel....turn low speed mixture needle ( the one on the left nearest the engine) in clockwise gently till it stops then back it out counterclockwise 1 to 1 1/4 turns. This should allow the engine to start...when it starts adjust screw in or out in 1/8 turn increments until you acheive a smooth idle...then throttle up and see if it will go to full throttle...you may have to adjust the high speed needle a bit to get a smooth transition from idle to full throttle...once you find this "sweet spot " turn the H needle 1/8 turn counterclockwise to allow it to run just a bit rich at full throttle. remenber when adjusting these needles...counterclockwise = more fuel...clockwise = less fuel !!! other things to check are, tightness of screws on carburetor, check the four screws on the back of the rear crankcase plate ( the rear part of the case that holds the gas tank on...the four screws above the gas tank) to make sure they are tight as any air leaks in either will make your machine a ***** to run or tune, there is a gasket under these plastic parts which can get warped by the heat of the engine allowing air leaks..check fuel lines for cracks sometimes they will get gummy soft, crack, and decompose....Now, as I stated earlier, if you are not getting fuel to the cylinder more than likely you have a clogged or gummed up carburetor and this will necessitate either a good cleaning or a rebuild...either is easy to do....if this is the case, google "Zama carbs" and click on Zama technical manual this downloadable manual will tell you all you need to know about cleaning or rebuilding your carb....Hope this gets you going...;-D

My riobi weedeater will start with a little starting fuild but will not keep running. the plug is ok and new gas. I sent it to shop & it ran a little for a couple of times but now wont run again .