This might sound crazy but get a can of glen 20 from the supermarket and take off that tiny restrictive air filter (i know it looks great but it really restricts air flow) anyway open throttle and give about a 3 second spray down the carby throat, let throttle close and hit the starter. That Glen 20 is about 90% alcohol and will fire up any motor straight away.

PS, if you measure around that air filter outside circumference you will find it is about 30% of a standard harley sportster air filters area, which means poor air flow and extremely rich mixture. I had one on my sportster but went back to screamin eagle ham can filter, now goes great.

Possibly the crank position sensor is on the way out.

yes get rid of that air cleaner for starter's

 

Geeee...there is no crank position sensor on a carb bike

The crank position sensor is inside the nosecone on the cam cover side of bike. My bike is carbuerator with a cam position sensor and ignition module.

I replaced sensor by disconnecting plug where it connects under bike. Tied a peice of string to wires and pulled them out through nosecone. Attached string to new cam sensor wires and a bit of spray lube on the wires, pulled them back through and attached connector to them. Mark  position of old cam position sensor with a  felt pen on sensor plate and wall of nose cone before you remove it. Put new cam position sensor in same position (refer marks) to start the timing process. Hard to see timing dots- try finding TDC mark and set advance with a cheap programmable timing light. E.G. idle at about 850 rpm. Using clear timing plug to see fly wheel.   Find TDC _ then turn timing light dial to how many degrees advance you want - Then carefully turn cam position sensor till TDC mark appears again. Tighten lock screws. Finished.

 

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