Sounds like a plumbing problem. Completely re-do all the fuel lines, and make sure the check valve is in the correct direction and working properly.

When you took the regulator off, did you orient the body with the casting bump forward when it was re-installed?

Go to www.ysperformance.com and use the running instructions to set the engine.

Don't fret the compression. If the valves are set correctly, the comp will increase when you run it for awhile. Make sure the valves are set at .003"