# Stihl FS130R surging.



## Cherokeedan (Feb 22, 2016)

I have a Stihl FS130R trimmer that starts easily, idles good but at full throttle it surges. I have cleaned the carburetor, replaced the fuel filter, replaced the fuel lines, changed the spark plug and cleaned the air filter. It runs at full throttle but surges and does not seem to have the power that it should. It will run all day long like this just is very annoying. What can I do?


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## bassfisher6522 (Jul 22, 2012)

The carburetor diaphragm is bad....it's the little thin piece of plastic...aka gasket between the the upper/lower body parts of the carb.


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## AVB (Nov 28, 2014)

List possible causes from the workshop manual:

Engine does not deliver full power or runs erratically


 Secondary air seepage through faulty gaskets on spacer flange


 Piston rings worn or broken Install new piston rings


 Muffler / spark arresting screen carbonized
Clean muffler (inlet and exhaust openings), replace spark arresting screen (if fitted)​
Air filter element dirty
Fit new air filter element​
 Fuel / impulse line kinked or cracked


 Pump diaphragm torn
Install new pump diaphragm​
 Decompression lever sticking
Install new cam gear​


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