Before I disassembled the engine, I took pictures, wrote notes, and put marks on all of the different parts so that there would be no chance of me reversing something. I was taking it for granted that the engine ran correctly as the person that sold it to me said. Today I passed by the hobby shop and just for the fun of it, asked the owner if he happened to have a YS 120 as in the back store room he has all sorts of stuff. He had an older YS 120 identical to mine and indeed the regulator housing according to the one he showed me is installed 180 degrees backwards. I will try to get out and see how it runs after reversing it tomorrow. This was probably all of my problems from the beginning. I am keeping my fingers crossed. [8D] If it is indeed reversed, I can't believe that it ran at all. Even though the ports line up, things are not flowing as they should.

I'll let everyone know...

Roy