[Vwdiesel] not diesel, chain saw fix question

[Bryan Belman]

been trying to get a chain saw to run all day.I put on a new fuel line, no primer on this old model, so I sucked fuel up the new fuel line to the carb, clamped the hose and connect to carb.no issue drawing the fuel with my fuel syringe, so right size fuel line it think.but it won't stay running, carb is not drawing fuel up the line.I can put fuel in the top of carb with my syringe squirter and it runs that fuel out, starts right up.  If I keep putting fuel in top of carb, it runs.but that should be enough to get the flow of fuel going, but no.
any idea.I have an identical chain saw as parts, should I swap carbs.  Both of them are from the  early 80's, but the one I am working on was new in box and I only ran it a few times a few years ago.
thanks in advance for any advice.
 Bryan Belman, Pt. Pleasant, NJ 04 Jetta Wagon TDI PD BEW, 100hp, 5sp -- running :<)04 Golf TDI PD BEW, 100hp, 5sp Tiptronic Auto -- running :<)82 Diesel Westy 1.9NA 1Y -- running :<)70 Type 1 Beetle -- Running on the road now:-)