# Echo chainsaw won't rev when hot



## gearren (Apr 3, 2005)

I have an Echo 440 EVL chainsaw that starts first pull when cold, cuts great. Lately however, if you shut off the saw when its hot and wait about 5 min, the saw will start, but it doesn't want to rev, you have to milk the rpms up for about a minute. Once I get the RPM's up and hold them up, it will runs fine from then on. Acts like its getting vapor lock. Never did this before, any ideas?


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## bbnissan (Nov 7, 2004)

Check the spark arrestor screen in the muffler. There should be two screws that holds on a little cover plate. Behind the little cover plate you will find a little tiny screen. Hold the screen up to a light...if you can't see alot of light through it, you need to clean it or replace it.

If you want to save some money, you can clean it using this little trick...

1) Hold the screen with a pair of needle nose pliers and heat it up with a cigarette lighter or propane torch until the carbon build up on the screen turns bright red.
2) Blow air through the screen while it is still bright red and all of the carbon will blow right out of it.


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## gearren (Apr 3, 2005)

I cleaned the screen as you mentioned, but that didn't fix the problem. Thanks for the suggestion. Any other ideas?


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## bbnissan (Nov 7, 2004)

Well, there are a number of things that could cause the condition you describe. It could be a vapor lock condition like you described, but I doubt that since Echo usually does a pretty good job of routing lines. It could, however, be a small crack or pin hole in the fuel line that is causing it to suck a little bit of air and starving the engine of fuel. Another thing that comes to mind is a bad fuel cap or fuel tank vent. Next time you run it and it starts to act up on you, loosen the fuel cap a little and see if the problem gets better.

The final problem that comes to mind is an improperly adjusted carb, but I also doubt that since you only experience the problem when the saw is hot. Usually a carb problem will cause it to run badly the whole time.

Hope this helps...


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## gearren (Apr 3, 2005)

I checked the fuel cap, then replaced the fuel line, neither solved the problem. I was able to get it to rev alright if I backed out the low speed jet, however for it to idle I had to max out the idle screw setting. So I rebuilt the carb, it runs better, however I still have to run the low jet alittle richer, which makes it harder to start when hot, but once it starts it's good.


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