Wonderboy leaf blower problems

I have a 6 hp little wonder leaf blower. Couldn't run unless half choked. Rebuilt carb completely. Still wouldn't run and when I half choked It has little power. Next day go out start it runs fine. Next day half power wants to stall. Next day fine...... I got so aggravated with it I took out to a shop. Problem is they couldn't get it to act up. But as soon as I got it home, well you know the story. Any ideas or suggestions would be greatly appreciated.
Agitated in Bainbridge Ohio.
Thanks

Tip most of the fuel out and try again then refill tank to the top & try again.
If worse with the tank low good chance the fuel line has cracked.
These really need to be pressure tested under pressure & vaccuum

bertsmobile1,
Tried what you suggested with no difference. However, it made me wonder about the gas cap. Started running it and when it started failing I pushed down on the gas cap and the problem went away as long as I kept the pressure on. This made me wonder if it was the gas cap leaking or pressure on the tank. So I squeezed just the tank on the sides to increase the pressure in the tank and the problem went away. Not sure where to go from here but would appreciate any suggestions.
Thanks, rossfrank

Try with the cap loose & tank 1/2 full.
Most caps have a vent in them.

It is a simple duck bill that can get stuck closed


No air in = no fuel out.

That brand is unknown down here so I have no idea how it vents.

I am going to try to fix this one more time before I give up. I hate to take anything in for repair but I may have to finally throw in the towel.
I have a 6 hp little wonder leaf blower. Couldn't run unless half choked. Rebuilt carb completely. Still wouldn't run and when I half choked It has little power. Next day go out start it runs fine. Next day half power wants to stall. Next day fine...... I got so aggravated with it I took out to a shop. Problem is they couldn't get it to act up. But as soon as I got it home, well you know the story. Any ideas or suggestions would be greatly appreciated.

I have rebuilt the carburetor, new oil, new spark plug and tried it with small amount of gas, medium amount of gas and a full tank. No difference.
Last thing I tried was to take the gas cap off and tape the cap opening with strong tape. It ran good. I did notice the tape started to bulge due to pressure in the tank. I bought a new cap for $6.00 but the problem still exists. My last thought is maybe the fuel source after it runs a while is getting cut off from the carburetor but I cannot locate a gas filter anywhere on this thing. It is a Briggs engine.
Any other suggestions would be greatly appreciated.
Thanks, Rossfrank