Cs-400 tune

[nwmo_aggie]

Fairly low hour echo cs-400 here. For some reason it’s developed an issue of not wanting to run off an idle. It had set unused for a couple months, but hasn’t given me fits like this in the past. Fortunately I’ve had a spare or my 500p to fill in, but would like to get this one going.

Saw will idle fine, if you creep the throttle open, might get it to 1/2-2/3 then it generally dies like it’s out of fuel. Might or might not start if you set the high idle throttle, if it does, it recs, then instantly dies. I tried once to run it with the impulse line disconnected, and seemed to run, but didn’t run it long that way for fear of something happening.

I’ve replaced the fuel filter and spark plug. New primer bulb, and lines hooked up as they came off. Spark screen is clean, and cylinder through the exhaust port looks good. I’ve replaced the carb with a new echo factory. Have tried a few different H/L settings I found on here with no improvement. Actually screwed those out completely and gently blew a little air in them, one at a time to not mix them up. Replaced the impulse line. I’m currently running with the fuel tank vent off, with no impact.

Im at a loss for what to chase next. Is there a check valve or something in the fuel line from the tank, that maybe I need to replace that main line? And if so…how do you get to it?

 

[boboptic]

Don’t know but have similar problems with mine

 

[jason sloan]

make sure that the lines into the tank are getting a good seal were they go thru the plastic. i had one same problem and it was not sealing were they go thru the plastic. but also rule of thumb if it wont accept gas unless choked the high jet is cloged

 

[SteveSr]

make sure that the lines into the tank are getting a good seal were they go thru the plastic. i had one same problem and it was not sealing were they go thru the plastic. but also rule of thumb if it wont accept gas unless choked the high jet is cloged

This is a classic symptom of a sticking/stuck main nozzle check valve in the carb. Zama's are known for this but any carb can do this. It is generally a non-repairable fault.

 

[Old2stroke]

Did both carbs act the same? Sounds like you aren’t getting fuel out of the main jet. Stuck closed nozzle check valve, restriction/leak in fuel line or weak fuel pump. When you operate the primer does it pump solid fuel or mainly air?

 

[dsell]

Disconnect the fuel line at the carb and connect a syringe. You should be able to pull fuel easily with the syringe. Try bypassing the purge bulb. Was the saw always cold blooded? Have you removed the cat?

 

[nwmo_aggie]

Still have the cat in this one, but limiters long removed. Both carbs behaved the same.

Primer pumps fuel.

I gave up. Took it to a guy. He replaced the fuel line, and cleaned the carbs. He had it running, but was back to it’s old tricks when I picked it up.

Final resolution was that the coil has failed. Put a eBay take off coil on it this week and runs as good as it always did.

 

[dsell]

If you bought it new and you have the receipt, the coils are supposed to be lifetime warranty. Lifetime means 10 years after the last production of the saw. But, you'd probably have more in labor than the coil costs. Jacks shows $95 shipped. That is my issue with Echo, their coils are high.

 

[mountainlake]

https://www.sepw.com/cart.php?suggest=69037789-4343-409e-81b5-055314c05d86 $58 . Steve

 

[dsell]

https://www.sepw.com/cart.php?suggest=69037789-4343-409e-81b5-055314c05d86 $58 . Steve

+$12 shipping.

 

[mountainlake]

https://www.ebay.com/itm/2558809593...jeXL1O8sfqMvYXM96KGjJTm7LIfK|tkp:BFBMnoekp-Nh


They even make aftermarket one if you want to go that route. I'd bet Stihl oem are not cheap. Steve

 

[nwmo_aggie]

If you bought it new and you have the receipt, the coils are supposed to be lifetime warranty. Lifetime means 10 years after the last production of the saw. But, you'd probably have more in labor than the coil costs. Jacks shows $95 shipped. That is my issue with Echo, their coils are high.

View attachment 1069354

I don’t know if I’d qualify. Think this is a 2012 model saw, I’d bought new from a member/dealer on here, don’t know if I got an “official” receipt…but pretty sure he did the warranty submission. I got a decent deal on a new take off coil & flywheel off eBay.