Thanks Alaskavan for the help but the file does not show the bit I need.
The image shows the part I am talking about it is no.12 lifter collar no.10 is the lifter valve, I do not know if the collar goes on before or after the valves go on.
Air and gas go in that side of the engine. If gas is spraying out, there is something wrong. Either one of the valves isn't opening correctly, or one isn't closing correctly or both. You should get pictures of the assembly and compare them to pictures of one correctly assembled. If you can post pics, I will look at a Honda 50 that I have and see if I can tell where the problem is.