what should the fuel pressure on a 2000 500 hp carb motor be

one motor is 8 to 9 lbs other motor is only 6 lbs and drops to about 2lbs when wide open fuel pump i aasume??

8-9 is a bit high, but okay. 2 is way bad. Your motor has Mech pump I believe?? so no regulator. check your lines for any kinks, check teh fuel tank pickup and if you have a check valve, make sure its not stuck. switch teh lines on the tank and see if teh problem follows to the other motor. if so, its the fuel pump.

2lbs is way low at wot. Low enough that you're lucky you did not lean out and burn a hole in a piston. You need at least 5-6 at wot. I woud say replace fuel pump asap.

Those Hp500 pumps need to be serviced every year or so..they are very easy to do yourself....you do not need to remove them from the engine...just unbolt the fuel pump from the water pump..2 bolts...you can suck the old fluid out and put new fluid back in..outdrive gear fluid works great..you should also take the diaphram apart and makes sure it is not cracked....be sure to watch where your lines are so when you bolt the diaphram back on you dont have to guess...

can be that the screen in your fuel pick up on the end of your tube is clogged with crap from the tank, or the gas tank breather hole is plugged and not letting the tank get air. "spider webs"

Thanks guys

the fuel pump fixed the problem