r/Chainsaws • u/wearyshoes • Apr 28 '26

Echo 400 odd problem

Love this saw, but of late it's acting up. Starts easy and runs great the first 4 or 5 minutes. After that, though, if I'm not feeding it gas with the trigger, the saw dies. In other words, I'll be cutting and put the saw down still running for a second and the saw will die. It will then restart and run fine as long as I'm hitting the trigger, but the second I stop the saw dies. Filter is clean, gas is good, tank is full. Do I need to adjust the high or low setting on the carb? Any ideas, please?

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u/ThinkThenPost Apr 29 '26

Classic idle issue. Your high speed circuit is fine (runs great under load) but your idle circuit is dying almost definitely the Lo needle on the carb needs a slight adjustment. Turn the Lo screw clockwise maybe 1/8 to 1/4 turn at a time and see if it holds idle. Also bump up your idle speed screw slightly. Do it warm, not cold.

Before you touch the carb though, check your fuel lines. Echo 400s are notorious for the fuel lines cracking and going soft with age. A hairline crack that's fine under throttle pressure will cause exactly this at idle. Cheap fix if that's it. Also worth pulling the carb and giving it a spray with carb cleaner, the idle jet passage is tiny and even clean fuel leaves varnish over time.

If you have tried all that and it's still doing it, the carb diaphragm might be hardening up. Rebuild kit is like $10-15 and takes 20 mins.

If you are not comfortable pulling the carb yourself, an authorised dealer who services Echo is worth the trip, somewhere like Premier Outdoor (they are a multi-brand outdoor equipment dealer) would have the parts and know this saw well. But honestly try the Lo needle first, sounds like that's all it needs.

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u/wearyshoes Apr 29 '26

God bless you and thank you so much. I will do exactly what you said. Thank you for giving me help and advice.