bystarter choke

[Wheelman-111]

Greetings:

Whoa, a lot to sort out here.

I suggest you begin by investigating for a vacuum leak. A spray of brake fluid in places like the bystarter socket, carb/manifold junction, the reed block, Crank seals, head and base gaskets will reveal a leak by some change in RPM, up or down. You can also use an unlit propane torch.

If your stock bystarter is still available, compare its dimensions to those of the Chinese replacement. Lots of unfavorable experiences with all things Chinese indicate that it sure could be the issue, but the behavior you describe is all over the place. It may or may not be the only suspect...