# String trimmer engine fuel starving



## johnshenry (Nov 16, 2016)

Hello group.

I have a Husqvarna string trimmer that I bought new, it is probably 28cc or so. I modified it by taking the string spool off and putting a 7" table saw blade on it. I use it to cut small pine saplings at ground level (usually 1.25" or less in dia) down on my property. Haven't used it all that much and the more I do, the more I have to choke it to keep it running. It usually starts and idles ok, but dies on throttle almost instantly. I have to keep the choke lever about 2/3 to full choke to just get it up to speed by feathering the throttle.

I realize that the engine/tool might not have been designed for that kind of torsional load, but I haven't used it all that much and can't imagine that torsional load could cause a fuel problem. 

Don't have the model number handy right now, but thought I would post here for help. I have a full shop and restore antique cars so am pretty handy with things mechanical... but 2 stroke engines have always been a mystery to me. Any recommendations for things to check/adjust? Fuel mixture, vacuum leaks? The tool is maybe 3 years old, bought from Lowes. 

Thanks in advance for any help. I really would like to be able to use this thing....


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## 30yearTech (Sep 14, 2006)

How old is the fuel? Old weak fuel can manifest as a carburetor issue when it's just the fuel causing the problem. Many times with ethanol fuels, internal check valves can start leaking and cause this type of issue. More often then not, it's cheaper and faster to replace the carburetor then trying to rebuild. Based on your description, it sounds like your not getting enough fuel.


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## finaprint (Jan 29, 2006)

Run with that internal check valve thing...........the valves form a fuel pump and ethanol laced or even standard type fuel will harden those little flapper valves to not move open and shut as fast and clean closed as they should be, then you get all kinds of running issues. I change that gasket and 9 times out of 10 back to great running. Empty the tank when done with the job and then run the engine until it dies to empty those little fuel compartments and the valves then last much longer as they are not sitting in fuel to harden up at the flex points. 

There is another very small metering valve in there that should be untouched at all times as it sets up the major fuel demand map, they are very hard to get back exactly right if you mess with them.


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