try a little oil on a q tip to the inside of the line that might help it slide on.
DO NOT leave it the way it is. That line is filled with pressurized gasoline and sits over a running engine. A little oil or grease on the barbed part and inside the line can help it slide on.
@Bob and @Scott:
Thanks for your suggestions. I took off that fuel line today. Applied a little oil on the barbed nozzle and very slightly applied on the inside of the fuel line with a q-tip. Pushed the fuel line as much as I could on the injector nozzle. The oil did help and this time the tube went further than before though it is slightly short of where the original was. Put the clamp back on. Definitely improvement from before.
I took the bike for a 40 mile ride with a couple of stops in between. Checked for any leaks when I got back home. There was none. I will keep checking it before / after every ride - next few rides - to make sure that fuel line is not sliding off the nozzle because oil can make it slippery. I will also keep checking that the clamp screw is tight.
The other end of fuel line fits perfectly and easily on the fuel pump nozzle, just like the original was ! The fuel pump nozzle is smooth plastic tube - no ridges / barbs. So the size (I.D.) of the new fuel line is ok. Also, the original line has stamp of 5/16, just like my new one has.