Try loosening it a little to let any debris that may be stuck in there escape, then re-tighten. If you do that while it's running, put a rag over the joint cause there will be some pressure.
Those pines have what Perkins calls an "olive" formed into the line. Basically a compression fitting.
It could also be cracked in which case you'll need a new line.
Hope the first thing solves it.
Sorry "Pack Mule" didn't see your reply while I was writing mine.
New Port Richey,Fl