Chainsaw Repair

Replaced all 3 fuel lines. New plug, new fuel filter.  One line in tank just had a plastic nipple on it with line going to primer ( wondering if it was a line with filter and other half of line and filter was just missing)? Then there was a skinner fuel line in tank with no filter on it.  I went with fuel filter on skinny line, being my WAG.

1 in the tank didnt even have a fuel filter. But I was told it would start and not stay running when picked up.  I tried to start and it wasnt happening. So I called and ask how many years has it been since it started and did you know there was no fuel filter.

Wore a freaking blister on my fingers trying to start this. grrrrrrrr.  Now waiting on carb kit now.

Also what kind of psi these little trimmer saw motors pull? 
 Wondering if ran with no fuel filter in past IF.............. pops ok and starts now just cant keep it running. reason for  carb kit.