Outdoor Power Equipment and Small Engines - Need help with Homelite trimmer engine

I have an older Homelite st-175 weed trimmer, it quit running so I cleaned it up and replaced some parts. Put new ring, carb. kit, fuel tank and spark plug, still can't get to start and run. It is getting a good spark through the removed spark plug when grounded. Is getting fuel, sometimes to much and I have set the needle valve when rebuilding the carb. The fuel pump lines are correctly attached. Are these machines just stubborn or what, it seems to want to run sometimes when I do not prime it, but only for a few seconds.... I'm not sure what the problem may be, anybody got any suggestions. Could the carb be warnout, if so what would be the obvious signs of this......need some help or should I just throw the thing in the trash......I really would like to find out why it will not fire off and run .............Thanks........

When it dies (when you do manage to get it started), what does the plug look like? Wet?

When it dies and I check the plug, sometimes it will look kinda dry and it also has been wet with gas. Seems that it will flood easily, I've found the crankcase loaded with fuel, so I checked the needle valve and leveled it. Do you think there could be a problem with compression or blowby, it seems to have pretty good compression...........Thanks for you help......

I think I found the problem with this Homelite engine not wanting to run.....I took the carb off my Echo and installed it on the Homelite. ran like a champ...do not know why it ran with this carb? Where can I find a carb that will work in place of the one on my Homelite?

Take the carb you removed to your nearest small engine shop and ask for a kit. Either walbro or zama and a kit is only a few bucks. Not much on those carbs to go other than diaphrams.