Echo PB-260L backpack blower carb issue

[bgsengine]

Well, I'm confused.

Wouldn't partially blocking off the exit air INCREASE the load on the engine? If you took this to the next logical step, and blocked off the air entirely, it certainly would.

Nope - its the same principle as with pressure washers - when it isn't spraying, water is under pressure in the pump but just recirculating (pressure equalized) thereby removing the load from the engine. whether it is air or liquid - if pressure is equalized, engine is doing almost no work other than maintaining pressure - using the same air/water that was there already, and thus, not loaded...

[Mek-a-nik]

The power required is a combination of air volume and air pressure, blocking the air outlet causes an increase in pressure but reduces the volume so the HP required actually does become less. Try it on any blower, it works the same. Requires less HP to maintain pressure than to move a high volume of air or anything else.

Okay, that makes sense. I was picturing it more as a positive displacement pump, or like having a clogged muffler.

Nope - its the same principle as with pressure washers - when it isn't spraying, water is under pressure in the pump but just recirculating (pressure equalized) thereby removing the load from the engine. whether it is air or liquid - if pressure is equalized, engine is doing almost no work other than maintaining pressure - using the same air/water that was there already, and thus, not loaded...

Got it.

Thanks, gents.

[jwales]

Just wanted to "close out" this post. I was not able to access the hi speed jet adjustment and I believe this was the "factory carb". I did put a new plug and filter in. Still could only get it to idle. It idled great! Found a replacement carb for around $14.00 and slapped it on...WooHoo it worked! This carb hi speed jet adjustment was standard screw head and with a minor adjustment was running full throttle, just like new!! Thanks for all the advice!