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Richard
Richard, Motorcycle Mechanic
Category: Motorcycle
Satisfied Customers: 3020
Experience:  Senior Mechanic & Technician
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Wont idle..throttle to keep it running, tried adjusting air screw

Resolved Question:

stihl weedeater, starts good reves up good, wont idle, have to play with throttle to keep it running, tried adjusting air screw but didnt help.
Submitted: 6 years ago.
Category: Motorcycle
Expert:  Richard replied 6 years ago.

RACE TECH :

How are you ?

RACE TECH :

Has teh weedeater sat for sometime without being used ?

Customer:

im fine thanks, XXXXX XXXXX? it gets used quite regular.

RACE TECH :

Yea but answer the question please

Customer:

sat over winter, and gets used once a week

RACE TECH :

What you should do is give it a good carburetor cleaning and check the fuel lines for any cracks. You may even consider a rebuid kit for the carburetor.

RACE TECH :

I have more for you

RACE TECH :

As gas gets old, it turns to varnish and clogs up the passageways inside the carburetor, not allowing enough gas to get to the engine.


This condition is cumulative. Every time gas sits, the varnish builds up just a little more, like coats of paint, until eventually gas can not flow. It will not happen overnight, but the symptoms can show up all of a sudden, even while simply stopping to refill with gas.


The use of fuel additives, such as Sta-Bil or Sea Foam will not stop this process from happening. They will greatly slow it down, but the gas will still go bad.


 


When this happens, either the engine simply will not start, or it will not run without the choke on (this reduces the amount of air getting pulled into the engine, changing the fuel/air mixture), or it will run but surges.


 


 


 


The only 2 solutions are to either replace the carburetor or give it a good, thorough cleaning.


When removing the carb, make sure to take a good picture, or make a good drawing of where all springs and linkages are attached. This will make reassembly much easier.


Most people believe that cleaning a carb involves removing the bowl and wiping it out, then spraying some carb cleaner through it.


This is simply insufficient.


To properly clean the carb, you must remove it, disassemble it (making sure to remove all non-metal parts), and soak it in a commercial solvent for several hours. Soaking it overnight is even better.


Then clean all solvent off with a spray type carb cleaner, making sure to get lots of cleaner into every hole and passage there is. Pay special attention to the tiny holes in the bore of the carb, under the throttle plate for the carbs that have these holes. Use lots of cleaner. And make sure to wear safety goggles to avoid getting the over spray into your eyes. There will be over spray.


Dry the carb with low pressure compressed air.


When reassembling the carb, make sure to use a carb kit, when one is available for your carb.


 


Occasionally, even a good cleaning is not going to be sufficient, and you may end up having to replace the carb anyhow. Be prepared for this.

RACE TECH :

I hope you have found my answer helpful. If I have helped you,please click accept. Clicking accept is the only way I am paid. Thanks & Goodluck RaceTech :)


You may be wondering how to reach me in the future, if you have another question. You can achieve this by requesting me to answer your question or in your new question, put FOR RACETECH.

Customer:

i njust bought it last fall, would it need that already

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