The relationship between mixture screws and idle speed screw needs to be proper. If the mixture screws are in too far, you can make the carb idle on the main metering circuit - though not very nicely. As Cloaked said, start with the idle mixture screws 1 1/2 turns out and get you idle speed set properly.
If the diaphragm on your power valve (and it should be 2.5) is ruptured, it will run full rich and give you black smoke coming out the exhaust. The only true way to test it is to remove it and hold the outer diameter of it while trying to gently twist the pointy end. If it turns freely it is bad. By turning your mixture screws in all the way, the engine can still run if there is a significant base gasket leak.
REBUILDING HOLLEY MARINE 4160 CARBURETORS - $199 DELIVERED
GENUINE MARINE HOLLEY KIT USED - INCLUDES POWER VALVE UPDATE
LED TRAILER LIGHTS, LUG NUTS SPARE TIRE CARRIERS, SAFETY CABLES....
Originally Posted by Bouyhead
Installed my carb that was rebuilt by thatsmrmastsercraft, Thanks Peter!! Hot or cold this boat starts and runs like it fuel injected.