I just need a new one. Where to order, if it exists...due to extensive battery corrosion, difficult to clean adequately.

It is possible to repair a Skytech 3002 receiver that has corrosion or a broken battery spring, but it will depend on the extent of the damage.
If the corrosion is minor, you may be able to clean it off using a soft cloth and some isopropyl alcohol. However, if the corrosion has caused damage to the electronics inside the receiver, it may be difficult to repair and you may need to replace it.
Similarly, if the battery spring has simply come loose, it may be possible to reattach it or replace it with a new one. However, if the spring has broken off completely, it may be difficult to repair and you may need to replace the receiver.
To replace it you can get a discounted one below

https://amzn.to/3EEZEsX

The fact that it starts when you jump it makes me believe it is not the started. I think a dirty, loose, or bad battery cable connection -- or it could be a bad battery cable itself.

Why are you replacing the CDI? If it ran properly prior to replacing the CDI then your issue must be with the replacement unit or handling. Is the CDI the exact model as the old one, is it new out of box? Check ALL connections! Make sure you have CLEAN terminals. No Grease, dirt, corrosion or any foreign matter. Remove and clean ALL connections. Any corrosion can block adequate spark. Including battery terminals, BOTH ends. Also, check to see if any fuses have blown.

Check out the battery cables for corrosion and for a tight connection. Usually a problem like yours is due to a loose cable or extensive corrosion on the battery cable ends. There are spray products available over the counter that work pretty well on corrosion or you can use a piece of emery cloth to clean the inside of the terminal ends. Since the starter requires much more power than the headlights and other accessories, it's not unusual for those to work and not be able to start the car.

Run a new wire from a solid ground point( like from the battery negative) to the black wire on the tail light fixture and turn on lights. If you have a working light then you'll need to find where that ground wire for the socket connects to the vehicle and inspect the mounting point for corrosion. Also inspect where the wire goes into the socket for corrosion and inspect the existing ground wire for breaks or lumps. If you cannot get the existing ground wire to work then you will need to replace the ground wire and mount it to a new ground location on the vehicle chassis or frame. When installing a new wire, make sure to coat all parts with Dielectric grease to ensure a clean connection and help prevent corrosion from building up. Also inspect your bulb socket for discoloration or corrosion. You may be able to clean out the socket using a water and baking soda mixture, depending on the severity of the corrosion. If you clean it out, use compressed air to dry out the socket and put a generous coat of Dielectric grease in there to help promote the connection. Hope this helps and thanks for using Fixya!!

1. Make sure you will install a new or fully charged battery/batteries into your camera. 2. Clean the battery contacts. a. Remove the battery/batteries and the memory card from your camera, then wipe the battery contacts with a soft, clean cloth. b. Reinstall the battery/batteries into your camera c. Without the memory card, turn your camera on. 4. Please test with the a different battery If you do not have access to another battery Try these steps instead: Please take the battery out of the camera. b. Insert the charger into the unit from the main socket and turn the camera on. If the camera works you will need to replace the battery. If you camera doesn?t switch on you will need to order a No power repair or a new cable. In order to organise your repair or Trade up please Contact KODAK: http://www.kodak.com/eknec/PageQuerier.jhtml?pq-path=14563&pq-locale=en_US&_requestid=3490

Removal & Installation

1. Remove 2/3of the brake fluid from the master cylinder.
   
2. Raise and support the vehicle.
   
3. Remove the tire and wheel assembly.
   
4. Remove the front wheel hub extension (dual wheel vehicles only).
   
   • Insert a drift or large screwdriver through the brake caliper into one of the brake rotor vanes in order to prevent the rotor from turning.
     
   • Mark the relationship of the front wheel hub extension to the hub
     
   • Remove the front wheel hub extension bolts
     
   • Remove the front wheel hub extension from the vehicle. It may be necessary to tap around the perimeter of the hub extension with a rubber mallet to loosen it from the hub
     
5. Mark the relationship of the rotor to the hub.
   
6. Remove the caliper and mounting bracket as an assembly.
   
7. Hang the caliper and the mounting bracket assembly from the suspension using mechanics wire.
   
8. Remove the rotor.
   
9. If the rotor is difficult to remove due to corrosion in the hub area use the following procedure to remove the rotor (25 series only).
   
   • Clean all the surface areas and the threaded holes of contamination
     
   • Generously apply penetrating oil or the equivalent to the hub/rotor area
     
   • Insert (2) M10 x 1.5 bolts (jack screws) into the threaded holes of the rotor
     
   • Tighten both bolts evenly to force the rotor from the hub.
     

To install:

1. Clean all rust and contaminants from the both side of the rotor and the hub flange.
   NOTE If the rotor was removed using the jack screw method you must ensure that the hub flange is free of nicks or marks caused by this procedure. Remove all raised nicks or marks before installing the rotor.
   
   
2. Install the rotor.
   
3. Install the caliper and the mounting bracket as an assembly.
   
4. Install the tire and wheel assembly.
   
5. Remove the safety stands.
   
6. Lower the vehicle.
   

It's difficult to troubleshoot your camera without seeing it, but your problem may be due to weak/worn out batteries or corrosion on the battery contacts inside the camera which can prevent the full power of the batteries from flowing into the camera. Try this free fix before you do anything else: remove the batteries and wipe the camera contacts firmly with a dry cloth (heavy corrosion may require cleaning with a wire brush, steel wool, or sandpaper). Remove any residue that may have fallen into the battery compartment during cleaning, then wipe both ends of the batteries and place them back in the camera. This cleaning clears the problem about 90% of the time. If it doesn't work for you, your batteries may need to be replaced, or the camera may have a problem that requires professional repair.

Assuming that the new batteries are the correct type for the camera and they are fresh/fully charged, your problem may be due to corrosion on the battery contacts inside the camera which can prevent the full power of the batteries from flowing into the camera. Try this free fix before you do anything else: remove the batteries and wipe the camera contacts firmly with a dry cloth (heavy corrosion may require cleaning with a wire brush, steel wool, or sandpaper). Remove any residue that may have fallen into the battery compartment during cleaning, then wipe both ends of the batteries and place them back in the camera. This cleaning clears the problem about 90% of the time. If it doesn't work for you, your camera may have a problem that requires professional repair.

It may be something more serious, or your new batteries may be defective, but the problem you describe is frequently due to corrosion on the battery contacts inside the camera. Remove the batteries and wipe the camera contacts firmly with a clean cloth (heavy corrosion buildups may require cleaning with a wire brush, steel wool, or sandpaper). Remove any residue that may have fallen into the battery compartment, clean the contacts at both ends of the batteries, and reinstall them in the camera. Assuming that the batteries are fresh/fully charged, this takes care of about 90% of the startup problems. I hope it works for you.