I have a new problem, and now I am back in my country, so it's going to be hard to return the engine:
I installed it on my plane. Gas gets to the carburetor, I have good spark, and everything seems fine; however, again I flip and flip and it doesn't even 'pop'.
I tried a starter, and, choked, it popped, and then I opened the choke and it Started with the starter and ran fine.
I tried to start it once again by hand, and nothing.
I used the starter again, and I had to close the choke once again, and then after it popped, open it and run the starter again, and it run.
Is it going to be impossible to start by hand? What could be happening? Again, all help will be greatly appreciated!