I had allot of trouble getting these white LED's to work in my Atlas GP-7. I just replaced the old ones in my Kato F-3's and RS-2's with no problem. I found that most (or all??) of the white LED's are rated at 3.3 vdc .030 amps. The Atlas led's are 1.5 vdc. The problem is, by the time you go fast enough to get the lights to come on your at Mach 1!! I tried all kinds of resistors and found that you can replace their LED with a white one, and replace their resistor with a piece of wire. Just be sure not to really crank up the power or you may burn them out. I know that the problem lies in the Atlas motor, but spending another $20 just to get the lights to work is a bit much. Has anyone got a better or different solution.