Echo CS-620p carburetor issue. Saw will not idle

[scarygary92]

Ive had saw alittle over a year, I replaced the carburetor a few months ago because the saw was having the same problem it has now. Its starts runs and cuts good. has good compression, Vacuum and pressure tested. I use 90 octane ethanol free fuel. As well as regular cleaning and maintenance. I opened up muffler a bit after I bought it, as well as pulling the limiter caps retuning. The first carb lasted about 8 months the second one i put on is now having issues. before i replace the carb again i was hoping someone could provide some insight as to weather or not this can be corrected. The saw will not idle cold and hesitates to accelerate. Once it's warmed up it will idle normal for a few seconds after coming out of a cut, then lean out and stall. No amount of adjusting on L makes a difference, but have ruled out an air leak. Before the stalling progressively started to get worse it would idle lean to the point the chain would spin slightly but would not stall. but it only did that sometimes.

 

[CausticUC]

What are your current H and L settings?

 

[North by Northwest]

Definately sounds like a L- jet lean issue . May be that there is some debris or varnish issues . I would 1st try a few ounces of carb cleaner in fresh mixed fuel . It may clean It out otherwise remove the jet and spray clean the fuel circuit with carb cleaner & tag wire !

 

[scarygary92]

What are your current H and L settings?

I set it to back to factory settings after my attempts to adjust didn't change anything. But they were factory settings still when It started developing the idle problem.

 

[scarygary92]

Definately sounds like a L- jet lean issue . May be that there is some debris or varnish issues . I would 1st try a few ounces of carb cleaner in fresh mixed fuel . It may clean It out otherwise remove the jet and spray clean the fuel circuit with carb cleaner & tag wire !

When this issue developed on the original carburetor, I thoroughly cleaned it and replaced all the gaskets and diaphrams. That did not help. Once I installed the new carb it idled fine, but now the new carburetor has developed the same symptoms. But why would two carburetors fail in a year? I'm wondering if there's something I'm doing that's causing it.

 

[CausticUC]

I set it to back to factory settings after my attempts to adjust didn't change anything. But they were factory settings still when It started developing the idle problem.

What do you call factory settings?

 

[North by Northwest]

When this issue developed on the original carburetor, I thoroughly cleaned it and replaced all the gaskets and diaphrams. That did not help. Once I installed the new carb it idled fine, but now the new carburetor has developed the same symptoms. But why would two carburetors fail in a year? I'm wondering if there's something I'm doing that's causing it.

Try some concentrated carb cleaner in fresh fuel , a tank will clean out any blockage , if that's the problem . If your running quality oil & 90 octane , you should be fine . Nothing I can think of other than fuel starvation within your stated symptoms . Depending on the oil ratio. & elevation retuning changes may be required , which is normal !

 

[scarygary92]

What do you call factory settings?

1-7/8 turns out for L and 7/8 turn out for H

 

[CausticUC]

1-7/8 turns out for L and 7/8 turn out for H

Those are the service manual settings, which are different than the original settings. Anyway (from a tractor forum):

"[https://www] Re: Echo CS620P Carb Adjustment

Boyde, I sent you a PM. I have a 620P I bought brand new in early February knowing it would need to be tuned right out of the box. EPA standards require them to be tuned so lean it isn't funny. I had to open my low speed jet over a full turn from the factory setting so it wouldn't bog when pulling the trigger. I also had to open the high speed a bit too but can't remember how much off the top of my head

"

Is where you should probably start. Your settings will also likely change in summer vs winter and it is guaranteed that it was never set properly for your altitude.

So, start at L 2 (go up towards 3) and get your saw to idle enough that it will get hot and let you set your H.

 

[scarygary92]

Those are the service manual settings, which are different than the original settings. Anyway (from a tractor forum):

"[https://www] Re: Echo CS620P Carb Adjustment

Boyde, I sent you a PM. I have a 620P I bought brand new in early February knowing it would need to be tuned right out of the box. EPA standards require them to be tuned so lean it isn't funny. I had to open my low speed jet over a full turn from the factory setting so it wouldn't bog when pulling the trigger. I also had to open the high speed a bit too but can't remember how much off the top of my head

"

Is where you should probably start. Your settings will also likely change in summer vs winter and it is guaranteed that it was never set properly for your altitude.

So, start at L 2 (go up towards 3) and get your saw to idle enough that it will get hot and let you set your H.

it's still does the same thing regardless of how much adjusting i do! I spent a solid 3 hours trying different settings to no avail...

 

[onofre]

Lo configuré para volver a la configuración de fábrica después de que mis intentos de ajuste no cambiaron nada. Pero todavía estaban en la configuración de fábrica cuando comenzó a desarrollar el problema inactivo.

Cual es el ajuste exacto de fábrica

 

[rmh3481]

Both the Walbro HDA-268 and HDA-316 carbs have what are known as semi fixed jets in them. This semi fixed jet gives direct access to the fuel in the metering chamber without being metered by the H jet. This design has been used many times over the years by different manufacturers. Echo picked it up because of their 5yr warranty. The idea is even if the H jet is lean, the semi fixed jet will flow enough fuel to keep the piston from melting.
If you remove the metering cover and the diaphragm/gasket from the carb (4 screw side) you will be able to see the semi fixed jet. Mine has .058 on it. So like I said, the SFJ flows fuel thru the high side nozzle whether you like it or not. Engine vacuum draws on the nozzle at high speed.
These nozzles are easily damaged by high pressure air, alcohol and some carb cleaners. If you had your air line in there its probably toast. Alcohol above 10% disolves the check valve inside the nozzle. Your going to have to dig out the parts schematic from Walbro and see if they offer a replacement. Some guys have been able to use a small dab of nail polish on the metering side to block the fuel access. Otherwise there is a Husky part number for a replacement nozzle that Ive seen on the forums. You can try the nail polish, but if the internal check valve is damaged your going to need a new nozzle. If Echo/Walbro wont sell that nozzle, then its either a warranty claim for a new carb, or a new carb you have to pay for. Ive also replaced that carb with an HDA-203 off an Echo 670 which does not use the SFJ. If you go this route you have to monkey with the choke linkage. Some guys have the tools to do this kind of work and others would rather just take it in. If you have questions send me a PM.

 

[onofre]

Tanto los carburadores Walbro HDA-268 como los HDA-316 tienen lo que se conoce como surtidores semifijos. Este surtidor semifijo da acceso directo al combustible en la cámara de medición sin ser dosificado por el surtidor H. Este diseño ha sido utilizado muchas veces a lo largo de los años por diferentes fabricantes. Echo lo recogió debido a su garantía de 5 años. La idea es que incluso si el surtidor H es pobre, el surtidor semifijo fluirá suficiente combustible para evitar que el pistón se derrita.
Si retira la cubierta de medición y el diafragma/junta del carburador (lado de 4 tornillos), podrá ver el surtidor semifijo. El mío tiene .058. Entonces, como dije, el SFJ fluye combustible a través de la boquilla lateral alta, le guste o no. El vacío del motor se basa en la boquilla a alta velocidad.
Estas boquillas se dañan fácilmente con aire a alta presión, alcohol y algunos limpiadores de carburadores. Si tuviera su línea de aire allí, probablemente sea una tostada. El alcohol por encima del 10% disuelve la válvula de retención dentro de la boquilla. Vas a tener que desenterrar el esquema de piezas de Walbro y ver si ofrecen un reemplazo. Algunos muchachos han podido usar una pequeña gota de esmalte de uñas en el lado de medición para bloquear el acceso al combustible. De lo contrario, hay un número de pieza de Husky para una boquilla de reemplazo que he visto en los foros. Puede probar el esmalte de uñas, pero si la válvula de retención interna está dañada, necesitará una boquilla nueva. Si Echo/Walbro no vende esa boquilla, entonces es un reclamo de garantía por un carburador nuevo o un carburador nuevo que tiene que pagar. También reemplacé ese carburador con un HDA-203 de un Echo 670 que no usa el SFJ. Si vas por esta ruta, tienes que jugar con el estrangulador. Algunos muchachos tienen las herramientas para hacer este tipo de trabajo y otros prefieren simplemente asimilarlo. Si tiene preguntas, envíeme un mensaje privado.

 

[onofre]

Muchas gracias