Onan LP Generator Problem UPDATE with new ?

The problem was the regulator diaphragm. The sd regulator is no longer made and had to replace it with a kn model. Got it all hooked up and everything was great. Let it run for about a minute and then put it in the trailer. Now it will not run unless the prime button is held, even then it runs at only about half speed and acts as if it is starved for fuel and dies if prime button is not held. Took it back out and checked to make sure nothing in any of the lines and bypassed fuel shut off.

Now I am really baffled. Any ideas are appreciated.

Thanks,
Casey