Ryobi weedeater cranks and idles fine but dies when throttle is opened...especially when you open it quickly. New gas...plug...fuel lines...primer bulb...carb rebuilt...muffler not clogged..running out of ideas. Any help would be appreciated since 2 "pros" have looked at it and can't fix it.
Weed trimmer fuel pumps dry out but they do not pump fuel into the piston chamber. The downward/upward motion of the piston pulls and pushes the diaphragm bringing fuel to the carb. That piston motion also pulls air in through the carb throat and that is what pulls fuel into piston. The fuel and air atomizes for a good burn. The fuel line from the tank is very small and ethanol can cause the line to get gummy. Remove the line and replace it with correct fuel line. the carb passages are small so any dirt or gum will allow it to run in idle or not at all. Some of the carbs have a fine round screen that fuel is filtered through but a drop of water cannot so it will block fuel. That can be found during a rebuild. Most problems are fuel line failure (clogged with dirt or collapsed/gummy) or mixture screw set wrong. I assume everyone knows gas has a shelf life of one month. Do not let old gas sit in the tank and carb all winter. It will turn to vanrish with an onion-like smell then it will dry and crust up then turn to white powder. Buy a new trimmer. Preferably an electric or if you must have a gas engine use ethanol free gas at around 87 octane, use quality spark plug and gap it right.
SOURCE: starts and idles and runs half speed ok -- dies off on full throt
Since you don't indicate the make and model, I can't give you specifics, but when I had this problem it turned out to be a dirty carb. This can cause uneven fuel flow and loss of power. At full throttle, you may not be getting sufficient fuel to work properly. Try cleaning the carb a nd update this with the results.
Dan
SOURCE: craftsman weedeater 316.970111 model//starts easy
I could not find your model based on the number you listed in your questions. Sears Parts Direct will have the schematics for your machine. Difficulty with starting the 2-cycle trimmer (especially if it has been sitting for 6 months or more) is common:
It is most
likely you will need to service the carburetor. Today's modern fuels
will, over time, gum up the carburetors and small passage-ways within
the carburetor making the carburetor ineffective. Diaphragms will become stiff and ineffective. A carburetor rebuild
kit can be a DIY project and are inexpensive. Common carburetors for the Craftsman is either Walbro or Zama. You will need to look closely at your carburetor to find the name and model for replacement carburetor parts.
You
can also remove the exhaust or muffler to visually insure that the
small screen (if applicable on your actual model) is clear of
carbon build-up. Clean/replace and retry.
Before you rebuild your carburetor or remove the exhaust, try the simple things below:
1. Air Filter maintenance. Your air filter needs to be reasonably clear. You can clean with water/soap, insure it is dry and lightly oil and replace.
2.
Replace your pre-mix fuel or determine that is no older than 2 months
old. I know you have done this, but insure it is fresh AND is of the
correct ratio (typically 23:1 to 40:1).
3. It appears you have done this, but if not Follow the fuel lines
(especially within the fuel tank) any deterioration in the lines will
allow air into the system which will contribute to a difficulty in
starting. Fuel lines > 6-7 years old often need to be replaced.
4. Remove the fuel filter within the tank and clean by blowing compressed air through the filter and using soap/water.
Retry. These are the issues to about 95% of starting problems for 2-cycle string trimmers.
SOURCE: I have a weedeater brand hedge trimmers 18 inches
have you checked the fuel plate thats in the bottom of carb? they tend to dry up and because rubber the 2 stroke fuel makes it dry and shrink, then it no longer pumps fuen into cylinder
SOURCE: I'm trying to get an
There are 2 different set ups for fuel lines on these 2 stroke carburetors. One has a remote primer/purge bulb and the other has the primer/purge bulb on top of the carburetor. Here are instructions on how both kind work and how to service them.
The small diameter line out of fuel tank (has filter in-tank on end) connects directly to the side of the carburetor that has the fuel pump....that is the cover without the hole in it. Other larger diameter fuel line out of tank connects to the longer nipple on the external purge/primer bulb. The bulb "pulls" fresh fuel from the fuel tank to the carb and then out of the carb to itself, where it then "pushes" any air/old fuel back into the fuel tank. The remaining larger diameter fuel line in this setup goes from the metering chamber (has cover with writing on it and a vent-hole) side of the carburetor to the smaller nipple on the purge/primer bulb. Again, on the primer bulb, the longer nipple has a line going directly from it to the tank. This is the return line. The shorter nipple on the bub has a line from it going to the metering chamber side of the carb. If the purge/primer bulb is on top of the carb...small line from carb body to small hole in tank with filter. Larger diameter line goes from the bulb on the fuel pump side of the carb to the larger hole in the fuel tank where sometimes the line is held in place with a nylon nipple connector that keeps the line from pulling out of the tank. Otherwise, the line should enter the tank for about 1/2" or so
If you have any more questions, please post back. I will see your comment and be glad to help you,
hello sir, my machine will only start when pumping primmer bulb or squirting fluid in the carburetor than stops. the fuel line has broken off, in most small carburetors this is a ongoing problem.old fuel will crystallize when left in tank for a long time.plugging up ports, fuel lines, small screen in carburetor.fuel lines will dissolve clogging carb.this is why it will run when the choke is on creating a vacuum to where there is fuel forced in the carb to rum,also the gas will evaporate leaving the oil behind clogging up carb.the thing to do is remove carb. and clean out,replacing gaskets or fuel line if necessary.use carb cleaner to clean out carb.make sure to make note where fuel line go.the fuel filter broke off of fuel line letting debris get in carb plugging it up.the muffler is known to clog up a lot on these machines where they want run. the compression should be 60 to 120 lbs any thing below 60 is junk. when adjusting the carb screws turn in all the way than turnout 1 1/4 turns turn in slow until machine runs also you need to check for spark by removing plug and grounding against engine to check spark, ok.a new spark plug would be a good ideal too , if you are going to make these repairs use new fuel line and filter,hope this helps,any comments welcome,thank you, !!
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