Not getting the fuel is the issue here. When you pull the rope you are cranking the engine faster than the electric starter turns the engine, that is why you can pull more fuel to start with rope. Primer is a good idea, but unit should start with the starter. I would check condition of the battery and connections real good, and check starter draw. Even though you don't have many miles on your unit you could have moisture in the starter causing drag on starter.

 

You may also want to check that the choke is operating correctly. The choke lever moves a little piston like valve in the carb and if the cable is stretched and/or the valve is sticking it will not open and the choke is not on. It is an easy hours work to clean the carb to make sure its operating correctly and fixed the problem for me when it happened.

SJ