I have a 1976 ski nautique with a ford 351 that I just installed a brand new QuickFuel M-600 Carb on. It had a Holly automotive carb when I bought it so I installed the QF marine carb to correct that. The engine/carb runs great other than one problem I’m having: When I’m running the boat under load (approx. 2000-2500 rpm) I am getting a sputtering. I have to pump the throttle on the boat to keep it from cutting off. The boat accelerates perfectly. I’m only getting the sputtering at that crusing RPM. I’ve checked all the fuel delivery options and it seems to be getting fuel perfectly. I also have two aluminum spacers between the Carb and the manifold. This is how the boat was setup when I bought it so I didn’t change that when I installed the new carb. I’m also having trouble with the idle. It starts off idling fine but when I bump the boat in gear and then return it to idle position, the RPM’s do not come back down. My cable is adjusted correctly. Any ideas? Thank you for your help.