Fuel problem

[MidMoTractorMan 0]

I have a wheel horse 520 H my problem is something to do with the fuel I have put new fuel lines on new fuel pump and it seems like it's not picking up fuel because I've got a clear fuel filter On it it will stay half full then it seems like once it gets warm I lose fuel in my fuel filter  I don't know if it's getting too hot and evaporating but I had bowed all the cooling fins and stuff  out I just took the float out thinking that the float may be stuck but I am out of ideas need help

[Ed Kennell 46,101]

Fuel tank cap vent may be clogged.     Try running  it with the fuel cap loose.

Screen in the tank may be clogged.     Pull the line off at the tank to check for free flowing fuel.

to the 

 

[gwest_ca-(File Mod) 12,243]

Are all the fuel hoses new. New hose is soft and will seal on the nipples. Hard hose will likely leak and allow the fuel pump to suck in air at the nipples. And the same will will not allow fuel to leak when not under vacuum so makes it hard to diagnose. The fuel pump will suck air if it gets a chance because it is easier to pump air than fuel.

Air can be compressed and expanded so a short vacuum pulse from the pump just plays with the air. The pulse does not have enough duration to pull a bit of fuel with it.

That is why electric pumps located near the tank are a good choice. Most of the fuel line is under pressure.

It is normal to see a fuel filter half full but they should never go empty. At half full the inside of the cartridge will have fuel in it at the filter outlet but you can not see that. 

[MidMoTractorMan 0]

All right everything that you guys have mentioned I've already tried my fuel cap is cracked so I know it is getting vented I don't think there is a screen because when I first got the mower the rubber grommet was dry rotted and was leaking fuel I pulled it out in one piece and put a new petcock in it so I don't think that's the problem all my hose clamps are tight on the fuel lines what  electric fuel pump would you guys recommend