ech 250 blower flooding

amosmoses1

Forum Newbie
Joined
Jan 17, 2021
Threads
1
Messages
1
hello everybody. i have a ech blower that seems to be flooding itself while just sitting on the counter. ive rebuilt the carb, ive installed a new carb, ive adjusted meter lever, ive put carb kit in new carb and vise versa. i have no more ideas. is there anybody out there that can help. thanks for all the help and god bless america. 6.5grendel
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
Echos usually have both a vent in the fuel cap and a stand alone vent.
The fuel system runs at a higher pressure than air pressure so if the vents are not working increased pressure inside the tank can cause the fuel to leak .
The fuel lines can crack where they come out of the fuel tank
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
75
Messages
10,110
Bert, It sounds like you don't understand how these fuel tank vents works. They do not release the fuel pressure; they only prevent the fuel tanks from developing a vacuum.

To the OP you did install the gaskets and diaphragms in the correct order? Also did you pressure check the fuel side of the carburetor once you re assemble it?

Also which Echo 250 blower you have? The PB-250, PB-250LN, or the ES-250.
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
They do both.
If the tank goes above the pop off pressure of the metering needle then the engine will flood out as fuel will be sprayed into the venturi under tank pressure.
That is why you both pressure test & vacuum test a tank
Most I have found draw in through the cap vent then blow out via the breather
Some caps are 2 way vented, Hondas are like that & some of the Stihls I have come across .
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
75
Messages
10,110
Well in 12 yrs of working on Stihl and Echo along many other brands of 2 cycles I have never seen a two way valve, only one way duck bill valves. Even the following has an one way duck bill valve
.
shopping
 

ILENGINE

Lawn Pro
Joined
May 6, 2010
Threads
39
Messages
9,865
If it has a remote primer bulb, the fuel lines being reversed or the valves in the primer bulb have failed allowing backflow can cause your issue also.
 

Hammermechanicman

Lawn Addict
Joined
Jan 10, 2020
Threads
49
Messages
3,485
I have worked on more 2 strokes than i can count and probably most of the 0xx series and newer Stihl saws. Every tank vent i have ever seen is a one way, usually some type of duckbill. Some saws when they get hot they can build enough pressure to pop off the needle and flood the saw but it was over 90 degrees the times i have seen it. Saws like the 031 with the tank vent in the cap were prone to clogging. The cheap poulan saws are famous for the duckbill in the cap failing and leaking fuel when stored.
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
75
Messages
10,110
If it has a remote primer bulb, the fuel lines being reversed or the valves in the primer bulb have failed allowing backflow can cause your issue also.
Now that is possible even the three random looked up ipl so carburetors with integrated primers. I had a couple Stihl Zama carburetors where the primer bases had failed check valves flooding the carburetor but the return line has to be submerged in fuel for this reverse fuel flow to happen.
 
Top