The antifreeze did not clean everything, but the engine sure moves. The main problem is gum in the bearing. I will try the oven + rubbing alcohol.

However, my main concern is the carb. I guess I need to disassmble it before I put everything in the oven, right? Plastics and rubber may disintegrate/melt in the oven. Piper chuck, what's your opinion about it? - Thanks!