[daltore]

They're only rated for 20 amps, and they come with their own 20 amp fuse. Although this fuse is replaceable with an auto-reset fuse, I would not suggest replacing it with anything other than the 20 amp auto-reset fuse. We've burned out a few of them with very little effort at all, they're not one of those things that's rated for one value but can stand much higher.

As for wiring them to the same Spike, that depends on the Keyang motor ratings. I don't know how much current they draw, however, that kind of motor generally is very low-power in comparison to other types of motors (since the worm gear reduction has so much torque, they design the motor with less power as to not strip it out, and because it's not generally necessary).

If at all possible, check the specs. If not possible, my instinct says it should be okay. Just keep the 20 amp fuse somewhere in the line.