I actually had a similar problem with mine a couple of months ago, I bought it non running and when I fixed it I would give it throttle but it wouldn’t rev and it even had some sort of knocking noise when I revved it. After tearing down the top end at least 3 times I made the conclusion that it was something electrical and it was. I think I replaced almost every electrical component, stator, flywheel, cdi, coil and it didn’t do anything. Basically one of the previous owners crossed some wires that shouldn’t have been crossed and it messed with spark timing somehow, I’m actually not sure which ones it were, cause there were a bunch of cutoff wires, like the brake sensor and tors and whatever else, it was somewhere under the hood. I think your having a problem similar to mine, I’m not saying it can’t be the carb or other stuff, but I think it’s spark timing, just check over all your wires and electrical stuff, idk let me know how it goes.
