I have a Ryobi weed eater that will not rev up.

Fuel demand rises when an engine is put to work and that is probably why it is dying - either the fuel system or the carb is incapable of supplying that extra fuel or in an extreme case the crank seals might be failing.

Assuming everything else is in good order and in the case of a carb with the customary two fuel screws it could be a matter of maladjustment. Correct adjustment is tricky and takes a deal of patience.
If partially applying the choke, strangler or cold start as it begins to die makes it recover somewhat, I suggest you take another look at the fuel system and then the carb adjustment.

Most common problem with weed eaters is the small fuel line breaks off inside of fuel tank usually flush with top of fuel tank - check to see if fuel line is still connected to weighted fuel filter inside of tank - replace if necessary. If fuel line is intact then adjust High speed adjusting screw 1/16 counter clockwise to allow a richer mixture - special tool may be needed to adjust - available on ebay. "https://www.6ya.com/callphilipforhelp

depends if u have the export only carb , because if you have the C.A.R.B. model it's not adjustable (other than idle) , if you have the export only version then there are two small plastic caps on side that can be moved aside and screws can be accessed to set HI and low speed jets

C.A.R.B = California air resource Beauru

Start with carb adjustment. Turn out the low and high adjusting needles 1 full turn, then adjust the choke.

Hi Mark, I own a shop, we will not work on ryobi, have you gotten 2 seasons out of it? If so thats probably as good as it gets. But you can check carb settings. In the USA they come with limiters on the adjustment screws, not too much you can do(break them off) back your adjustments counter clockwise 1half turn.

I think a new carburetor kit and a good carburetor tune up is in order my friend. Sounds like it's starving for gas. If it bogs down after warm up when you throttle it, then yes it needs a carb tuning. The L screw is the low side screw and should be turned in lightly until it seats then back it out one and quarter turns (1 1/4). The H screw is your high speed screw. Also, turn it in lightly until it seats, then back it out approximately a 3/4 turn. With these settings the unit should start and may even stay running. Again, if it bogs when throttled, while running turn the L screw out a little more maybe only 1/16th of a turn and then try it again. If it does rev then you'll have to adjust the H screw in about a 1/16th of a turn. But make sure you only do this after the engine has warmed up.

Hope this works, good luck
Skidooer

Check the carb jets, they might be a gummed up!

Need to get the carb rebuilt..

Youwill need to disassemble the carburetor and spray with carb.cleaner.Make sure the small screen is free of debris. (Should be able to seedaylight through it.)

Use a Den Tek Brush, (http://www.drugstore.com/products/prod.asp?pid=165357&catid=1152),to clean the small portals in carb. These portals can become blocked. Reassemble and start.


If you need further assistance, just let me know.

Jim

you need to adjust the carb ,look for small screws around carb turn out 1/4 to 1/2 turn good luck