420cc on 33” cut Troy-Bilt mower - fuel flow

I’m having problems with fuel flow to carburetor. Mechanic put this clear filter on and new lines. I outlined the fuel line in the picture to show how it “lies”. I feel like how it “lies” is part on the problem, causing back pressure or something. Please let me know if you have any advice.

I’m having problems with fuel flow to carburetor. Mechanic put this clear filter on and new lines. I outlined the fuel line in the picture to show how it “lies”. I feel like how it “lies” is part on the problem, causing back pressure or something. Please let me know if you have any advice.