Small Engines (Lawn Mowers, etc.): Echo PB 260 Blower wont accelerate, echo trimmer, leak down test

Question
Hello Eric,
I have a Echo PB260 blower.  Serial # 05029920. It starts easy, idles fine and accelerates to about 1/2 throttle and then falls on it's face.  I have checked and taken out the spark arrestor and found no blockage.  It has a new carburetor, compression is 110# and has gone through a leak test. It held compression.  Changed the fuel filter and vented the fuel cap to check against vapor lock. Put in fresh gas and new spark plug just to be sure. I even changed the coil out with another blower of the same type to eliminate the possibility of misfire and nothing changed.  I have disconnected the throttle and tried to accelerate manually but the same problem exists.  When I try to accelerate to full throttle the blower acts like it is governed down.  It won't die but won't throttle up. I am out of ideas to try.  Has Echo had any similar problems with the blowers in the past?  Thanks in advance.

Answer
Have had ignition coils cause this problem but you said you switched one out.  Spark arrestor is also common to your problem...but you said it is clean.  Did you remove the muffler and see if the engine will accelerate?

What about the intake gasket and insulator block gasket?  The Echo trimmer I still use today was a free-bee from another shop because they could not fix it.  Took me several months, off and on, to finally find the problem (would not accelerate).  Turned out some replaced the carb to insulator block gasket with one with a small diameter opening.  Replaced the gasket with the correct one and runs great to this day.

Did you do a cylinder/crankcase leak down test?  A leaky crank seal or gasket will also cause no acceleration.

Let me know.
Eric