Carburetor Problem on aA Echo PB2100
I have an Echo PB2100 blower that is approximately three years old. It has been running poorly so I began to service it beginning with changing the spark plug, air filter, fuel filter, the vent filter, the fuel lines, and the fuel line grommet. This did solve the problem so I then rebuilt the carburetor (Zama C1U K68/28A). This entailed all the gaskets/diaphragms, check valve/spring/check valve arm and welch plug. I also changed all three intake gaskets. I thoroughly (3 times) cleaned the carburetor inside and out including every port.
On the exhaust side, I thoroughly cleaned that out and also put in a new muffler screen.
This Zama carburetor is slightly different than that illustrated on the diagram provided from Partstree.com. The high speed needle valve does not utilize a spring and washer and the low speed port is plugged off.
After all that I have done, the problem of the engine dying out when you depress the throttle still persists. I have taken the unit apart many times to make certain I have done nothing wrong, but yet it continues to do the same thing. It starts with no problem; and after I take it apart, it will run OK for a minute or so. Then it again begins to dye out. Adjusting the needle valve does not solve the problem. What can I do next with this most frustrating problem. One I have learned though is that I can disassemble the intake side of this unit in about two minutes. How about some help?