I don't have a lot of experience with that type of dual fuel system but I believe that the primer button is only an aid during starting. I also think it's natural for the system to sputter a bit when you switch back and forth because the propane has to start flowing from through the propane fuel lockoff as the gasoline is shut off to the gasoline carburetor. Because the hoses are so long from the converter to the mixers, the primer button can help to get the fuel to the mixers a bit quicker during a cold start.

I am not aware of any installers in Oregon but that doesn't mean that there aren't any. I checked superpages.com for propane conversion shops in Portland and didn't see any. You could try the lift-truck shops. Failing that, I think there are a few service centers in Seattle: http://cars.rasoenterprises.com/Prop...Facilities.htm

Frank