2 weeks ago riding home my bike quit running like it ran out of gas, wouldnt start again. Upon investigation I have no power to the coil hence I have no spark. Thought about changing the cdi unit but dont know for sure if thats the problem. Please help if you can.

1993 Sporster xlh 883.

 

You mention no power at the coil, so I'm assuming you have something to test the flow of electricity:
A few things to check.
Battery to main 30A fuse, then main fuse itself.
Main fuse to ignition switch
With ignition "ON" power up at the run switch
Switch in the "Run" position to coil

In your case I would look at two things first... Fuses, run/kill switch

Mine recently had similar symptoms, what I found on mine was the coil was defective and the rotor screw (part #19, #3) came loose throwing the timing way off. All I did was realign the rotor in the grooved slot, tighten the screw. Word of caution if you do decide to look at the rotor. Before loosening the screws to the sensor(#18) take a sharpie and mark a line on the edge of the sensor and the housing so you can put it back together without screwing up the timing.
See linked diagram for part numbers.
http://partsfinder.onlinemicrofiche....-COIL-ASSEMBLY

Good luck, let us know how it goes.