Johnson 175hp fuel pressure

[KILLERME]

Hi there, I have 12hrs on rebuilt premix two stroke just wanting to know if fuel pressure should pulse at idle or needle should read steady, specs are 2.5-6psi.
Because when had gauge on when was fresh built run for first 2hrs I am sure the reading was steady on 3 psi at idle. The weekend after when going to test full throttle pressure I saw it was fluctuating wildly 2.5 - 0 psi at idle. Fuel pumps have new kits, when did kits I did notice one pump had different size plastic diaphram washer inside it which spring sits on. In parts manual it does say pumps have different part no. I know outlets are differnent on pumps but should the guts of pumps be different. I am thinking should I just buy two new pumps to fix problem. I am sure pressure should be steady, becasue what I was seeing on gauge was fuel being pushed and pulled?

[jonesg]

Why dontcha post the year and model number.
I would look at the vac line check valve in the block that powers the pump but I don't know if yours has one, mine does @ 150hp 1994. J150wtcler.