Yes at first it was a really loud pop after me changing a few things it’s more of a sputter through the carb

If it ran great on the dyno but now it’s popping so the issue is likely in the boat, not the engine. Fuel lines degrade, anti siphon valves stick, crud and water in the tank. The mods may have pushed the line capacity over its limit?

Id start with bringing an auxiliary tank and run off of that for a few minutes then if it runs great then start with checking the anti-siphon valve and replacing the fuel lines. You may do well to drain the boat tank into your truck as well.

Its been twenty years years since I’ve touched a Quadra jet but some carbs can blow out a gasket etc if the back fire was gnarly enough.

Well I think I got it figured out. My main wire harness was not making good contact. Thank you for all the help guys lots of great information on here