Well, speaking of changes...over the thanksgiving weekend, got sick of constantly fiddling and diddling with that old Tillotson carburetor. It looked the part, but I just couldn't get it to idle right and it was constantly stalling; just plain old and worn out I suspect. I'll hang on to it as it would be great on anything that ran at a constantly higher speed.
Anyhoo, I replaced it with a carb off a 4.5hp Techumseh lawnmower engine. Finally, now it idles perfectly, runs perfectly and no more low speed stalling. It had no choke of course and the primer does work, but I thought it might look better with a little velocity stack and fitted a choke plate to that. Also did a bit of fiddling with the brakes to try to get them to stop the bike a bit better.