CS- 370 Carburator.

fayjim2

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Carb P.N. there any real difference between WT-829 A021001330 and A02100331 other than 20$ in price? Thanks Jim
 

hlw49

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Carb P.N. there any real difference between WT-829 A021001330 and A02100331 other than 20$ in price? Thanks Jim
Says A021001330 is superseded to the A021001331. Without having the two carbs. side by side there is no way to tell. When you look up the CS370 there are 9 serial no. breaks in the parts lookup.
 

fayjim2

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What are the initial settings L/H for the needle screws. I removed the caps and found low at 1 1/2 and the High at 3. Could that be a reason that it won,t rev when you ask for power/throttle response?
 

hlw49

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You didn't really say what the problem was. Is it just low on power and doesn't rev up. That could be a clogged exhaust screen or even a clogged exhaust port. I would check that out.
 

fayjim2

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Correct won,t Rev unless you pump the throttle.. When you finally get it up to rpm it runs and and does great. I have previously changed plug fuel filter exhaust screen and it changed nothing. Once again I tried to adjust screws but not any change. Thats when I removed carb and rmoved red caps. I think the h was opened to much? If you know the base settings I would appreciatethe settings.
 

fayjim2

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How can I find out the base settings. I just received a genuine echo carb. The red caps are not completely installed so I can dial it in.
 

StarTech

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Find someone with the Echo NA carburetor adjustment manual or ask a dealer if he will provide a snap shot of the instructions for your machine.
 

bertsmobile1

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1.5 L & 3 H sounds ball park.
The new eco carbs have finer needles to make them easier to tune & allow greater accuracy.
This is true if you the very expensive exhaust gas analysers but it makes it a bitch to do by ear because the difference between too rich & too lean can be 2 turns in place of 1/2 to 3/4 turns
So if you can get it up to full throttle , hold it there and turn the H needle out till it start to miss ( rich) then in till it starts to miss (Lean) then back to the mid point .
Note the difference in exhaust sounds while you are doing it .
Slowly back off and if it sounds like it is going to stall, turn the L needle in whichever direction makes it run fastest
Try to remember the sounds it made before when you adjusted the H needle , rich sounds soft & fluffly lean sounds sharp.
When you have it so you can back the throttle off till the chain stops then go back & readjust the H needle and then the L needle.
You may need to cycle through this a few times because the L is always supplying fuel where as the H should cut in at about 1/3 full revs.
You can do it the other way by starting with the L but usually it will stall out a dozen times so doing the H first I find easiest .
But you have not finished.
Final adjustments really need to be done "in the wood" so the saw is under load.

It is safest to have the engine a tiny bit rich than a little too lean

And light touch on the drivers.
The longer thinner needles are very easily damaged .
 

StarTech

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Go ahead and do possible cylinder/piston damage if the OP runs it more than 10 seconds at full throttle during adjustments before the engine return to idle for cool downs. Especially if the H adjustment is too lean. There is also a max rpm that should not be exceed as engine damage can occur.

That is why an Echo tech goes by the following table info with info provided by Echo on the whichever model the tech is working using a tachometer. Using their adjustment procedure the saw never need to put in the wood. [table scrubbed of adjustment info for all models; just shows the header and comment sections]
1638611948245.png
 
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