nter. I have cleaned the carburator and the muffler screens, to no avail. I have 92 octane gas and using echo oil, with stablizer. any ideas what to try next?

Experienced gardeners share their insights in answering this question :
Nichodemus, you can thank the epa for this. All of the 2-stroke handhelds now come from the factory set up very lean. Almost every new 2-stroke that I have bought in the past few years has needed a carb adjustment, both on the low speed needle and the high speed needle. There are tamper resistant plugs over the adjustment screws on most carbs now. Unless you know what you are doing, the dealer will have to do this.

How to Identify and Fix Common Gardening Problems ?

We provide a variety of viewpoints on how to identify and fix common gardening problems. Our sources include academic articles, blog posts, and personal essays from experienced gardeners :

Over time, the spark arrestor can become clogged with soot. If the spark arrestor is clogged, the engine may not start. To unclog the spark arrestor, remove it and clean it with a wire brush. You may also replace the spark arrestor.
Find the adjustment screws on the front of the carburetor.

There should be two screws on the front of the carburetor, which are used to adjust the air and fuel mixture. These often look like flat-head screws, and you can use a screwdriver to turn them, adjusting the amount of fuel and air mixing in the carb.

If your 2-stroke brushcutter fails to start, the simplest explanation is that there is not enough fuel: in this case you simply need to top it up. A 2-stroke brushcutter engine runs on fuel/oil mixture, which you can buy ready prepared, such as EFCO-Mix Alkilate alkylated mixture in a 5 L can.
If the trimmer engine runs, but the trimmer head does not spin when the throttle is engaged, the clutch may be broken. The clutch prompts the drive shaft to start rotating once a certain rotational speed is reached and allows the engine to run without always rotating the drive shaft.
Clean the Exhaust Spark Arrestor Screen

As with plug fouling, too much oil in the gasoline, inferior oil, a dirty air filter and/or continued operation at less than full throttle will plug the screen with carbon deposits. This prevents exhaust gas flow, which leads to power loss.

The idle air control valve enables the engine to idle smoothly rather than stall out while the vehicle is stopped. It will continue doing so until you step on the accelerator and the vehicle starts to move again. In gasoline engines, engine speed depends on airflow, which is controlled by the throttle body.
Pilot Jet – Pilot Screw

The pilot jet, also referred to as pilot screw, controls carburetor fuel/air mixture between Idle and 1/4 throttle.

Q: How Do I Know if My Carburetor Needs Adjusting? A: Simply put, poor running conditions are a dead giveaway. A rough idle, poor throttle response, and excessive fuel consumption are all signs to look for. If the carburetor was sitting for some time or hasn`t been serviced in a while, you may need to clean it first.
One reason why one of these trimmers may die at full throttle is that too much oil is in the gas, which causes poor combustion. Improper operation, including overuse of the choke, can also be responsible. Poor combustion produces carbon deposits that foul the spark plug and exhaust port, making the problem worse.
A clogged carburetor is most commonly caused by leaving fuel in the string trimmer for a long period of time. Over time, some of the ingredients in the fuel may evaporate, leaving behind a thicker, stickier substance. This sticky fuel can clog up the carburetor and cause the engine to stall.
When your trimmer starts and runs on choke, it could be because the check valve in the gas cap is clogged. Start the trimmer and gently unscrew the gas cap halfway off. Turn the choke off and assess. If the engine is still running, that means the gas cap may be the culprit.
If the carburetor is new or has been rebuilt, you should set it to “factory” adjustment. You can do so by adjusting the idle mixture screws to 1.5-2 turns out, and the idle speed screw to 1-1.5 turns in. Warm the Engine Up. The engine`s running temperature directly correlates with proper air and fuel mixtures.
So, an air filter might clog over time. Once blocked with dust and debris, it cannot supply the required amount of oxygen to your trimmer` engine resulting in power loss. Find the air filter, take out this component, clean and reassemble it. Replace the part if you cannot reuse it.
Locate the idle mixture screw and turn it clockwise until the needle lightly touches the seat. Then, turn the screw counterclockwise 1-1/2 turns. If your carburettor has a main jet adjustment screw at the base of the float bowl, turn the screw clockwise until you feel it just touch the seat inside the emulsion tube.

Discover Relevant Questions and Answers for Your Specific Issue

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Oil to gas ratio – RTO Echo Pb-755 Backpack Blower In Box
ANSWER : The ratio is 50:1. You can usually by oil in a container that matches the size of your gas can, takes the guess work out of it.

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Blower starts and runs for 5 seconds and cuts off. Is it an oil to gas ratio. Is is 32:1 or 40:1? For the Echo PB250 gas blower.
ANSWER : I don’t think the oil-gas ratio will cause that problem. Did you check to see if the fuel lines or fuel filter is clogged?

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Does not start
ANSWER : Any 2 cycle oil is good. Use a 40:1 mix to start with if it smokes then cut it back to 32:1 but its better to have more oil then not enough but start with 40:1

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Starts runs a couple of minutes then dies – Echo Gas Blower 135 MPH390 CFM Blower PB250
sounds like you have a bad Ignition Coil (Module). This is how they act
when they start going bad. When they get warm, they quit. Some will
last up to 20 minutes before they shut down. You can sometimes find a
used one pretty cheap at a small engine shop.Jim

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What is the oil and gas mixture ratio for a gas powered leaf blower?
ANSWER : Per http://www.echo-usa.com/faqs/ it 50:1, there is a chart at the site that shows how to mix it.

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Why does the echo start but die when i move from cold start to run?
ANSWER : Fuel issue, carb adjustment, fuel lines, carb rebuild.

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I have a pb-251. replaced carb, air filter, hoses, spark plug and cleaned spark arrestor. start easily. runs fine for 2 minutes and then stalls if I give it the gas but will idle all day long.
ANSWER : Loosen gas cap. Probably a bad Vent in the gas cap

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What is the ratio of gas to oil for the 63.3cc engine?
ANSWER : Hi, 25 to 1 which is 200mls of oil to 5 litres of gas. Regards Phil.

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