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Discussion Starter · #1 ·
Hey all I have a husqvarna 450 chainsaw. It for the most part has been a great saw.. However today one of the fuel lines came off the primer bulb. SO after fixing that the saw started"ok" idles "ok" but if you give her full throttle and you let off.. It will idle down straight to shut off.. However if you feather the trigger down it will idle "ok" for about 5 sec than shut off. Than to restart you have to "half choke" the saw (not sure if that's what it is called) choke up than push down just a little so engine runs at higher rpm. .. Any thoughts?? than
 

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Check that the filter is still on the hose in the tank. If you haven't been using an ethanol mitigating additive, you could have an issue with softening/dissolving fuel lines caused by the ethanol in the gas.
 

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Discussion Starter · #3 ·
Ill have to loo kinto that.. Never used any additives in the fuel we use.. I've heard that ethanol plays havoc on power equipment, but have never really experienced it... We usually have a pretty fresh fuel mix. However the latest mix we have was not done personally by me and I have no idea how "exact" it is.. Nor the quality of gasoline used. But also haven't really experienced this on a saw.
 

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Try giving the carb a good cleaning with some like B12 Chemtool.

Airfilter & intake also.
 

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Sounds like air getting into the fuel lines, that's would cause it to not idle. I would replace all the fuel lines just to be safe, ethanol can and will disentigrate fuel lines causing air leaks.

The mix ratio won't cause your saw to not run, unless it's way off. Just cause it to run a little lean or rich.

A great website for parts and help:
http://store.chainsawr.com/blogs/tu...djustment-and-tuning-of-a-chainsaw-carburetor
 

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The carb may have a blocked low end passage, or the pumper diaphram may have broken down, or as stated, there might be an air leak.

I had an old 3.7 cu inch (60cc) Craftsman of '78 vintage act like that, & it was the pumper. Kits are about $7 or so.
I originally thought it was the main seals going bad on mine, because of the way it acted lean, especially at low end. My brother told me it was the pumper...which it was.

Try Jacks. You could easily rebuild, or just swap out carb:
http://www.jackssmallengines.com/Pr...-Parts-2-Cycle/Carburetors/506450401/622670/s

Most chain saw use Tillotson pumper carbs, but I don't know what Husky uses.

One more possibility (but doubtfull in your case) is a broken down fuel line pickup in the tank. I had that happen also, but the symptoms were different.

Joe
 
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