Here's the problem: I have an Echo leaf blower model PB-4600, many years old, which starts easily & runs fine for the first two minutes until it warms up. Then, if you keep on the throttle, the revs suddenly drop and it stalls. If you release the throttle as soon as the revs drop, it settles into a nice idle. If you then increase the throttle back to operating speed, it will rev for a few seconds, then the revs drop again, etc. Pretty frustrating trying to blow leaves this way.
I've adjusted the carb according to the manual, didn't help. I suspect some other carb issue but the puzzling thing is why the problem only happens when it's hot. My next step is to take apart the carb and soak the parts in gumout but, before I did, I wanted to check in to see whether there was a known solution to this problem or if anyone has suggestions on what else to check. TIA.