Your track is O27. I think the lock-on (power feeder clip) in your pictures was designed for the taller O gauge rail. If the lockon doesn't snap on all the way and make good contact with both the outside and center rail, you won't have reliable operation. You might be able to increase tension by bending the piece of metal that clips to the center rail.
Adding a couple more connections can't hurt, but that's a band-aid work around to poor track joints. Make sure the sockets at the end of the rail where you insert the pins are nice and tight. If they're loose and sloppy, the loco will slow down or stop near that section because it's getting less power. A weak joint can sometimes even feel hot to the touch! You can try reshaping loose joints with careful use of needle-nose pliers. If the sockets are so wide or badly distorted that they won't hold a pin snugly even after adjustment, then you might need to replace that section of track. If the joint is tight but still doesn't conduct electricity reliably, try cleaning out the pin sockets with a pipe cleaner soaked in alcohol.
You should also pay attention to the loco wheels and pickup rollers. If the rollers are badly grooved or the springs are weak, you'll see sparking and stalling. Likewise if the loco wheels are dirty. A quick way to clean the wheels, is run the loco upside down and lightly hold an alcohol-soaked, lint free cloth on the wheels. A lot of grease will come off on the rag. Be careful not to get cloth fibers caught in the gears.
Any sparking should be reduced after several laps around the track. If the stalling doesn't improve it could be a loose wire, worn motor brushes or brush springs. Replacement parts are available. If there's heavy sparking, the motor might be drawing too much current. That can be a sign of mechanical problems like something binding or rubbing in the gear train. The 2023 and 2046 are both excellent locos which will run great on O27 track, once everything has been gone over and brought to good working condition. Good luck!
