Echo cs590 carburetor

[a. palmer jr.]

Working on a friend's 590 and it seems to not want to idle too consistently. It has the pulse hose through the top(fuel pump) of the carburetor and two manufactured holes in the top plate of the carb also. It looks like to me it would create an air leak in the saw or is there something I don't understand?

 

[a. palmer jr.]

Also thought I'd mention that on most carburetors you can pressure test the inlet of the carburetor but noticed the Walbro 268A doesn't hold pressure, I assume because of the two holes in the top.

 

[a. palmer jr.]

Not sure what happened, I soaked the carb in cleaner for 3 hours, put in a new fuel filter, checked the tank vent which was okay, filled the tank with mix and she fired right up!

 

[pioneerguy600]

Working on a friend's 590 and it seems to not want to idle too consistently. It has the pulse hose through the top(fuel pump) of the carburetor and two manufactured holes in the top plate of the carb also. It looks like to me it would create an air leak in the saw or is there something I don't understand?

Holes in the cover on the metering side is normal, it lets atmospheric pressure act on the diaphragm as required. On the pump side would be a no-no.

 

[a. palmer jr.]

I guess those two holes are blocked by the gasket or I suppose it wouldn't run. Funny I never noticed other saws having holes in the pump cover. I checked ebay for their 590 carbs and they had the holes also...

 

[pioneerguy600]

I guess those two holes are blocked by the gasket or I suppose it wouldn't run. Funny I never noticed other saws having holes in the pump cover. I checked ebay for their 590 carbs and they had the holes also...

Something would have to block them on the pump side, I can`t think what they were any good for.