Late model side distributor 8N. Tractor ran perfectly for years. Started first turn. Then started to stumble and run roughly. I had a carburetor kit here so decided to refurbish the carb. Bad idea! When I finished and installed the carb the tractor did not want to start. Frustrated, I ordered one of the Chinese built replacements. I installed it and the tractor started and ran fine until under load when it would stall. I opened the main jet and it seemed to be better but not right. So….I changed the points. The set I removed were burnt but, even with the new ones, it continued to stall under load. So, I will go back to original. At this point I would like to have someone who works with these original MS carburetors look at mine and see what the problem might be. I am in Ontario, Canada. Any suggestions? Dave