Gas in the Oil Pan. Need help. A 460.

[Jbm\Avenger]

Bought a 1978 Avenger bubble deck two years ago that ran two days before purchase. The boat was no Gem :) , but it ran supposedly. After purchase and having the carberator rebuilt and having all new gaskets placed on the motor. This engine has yet to run. The motor will start and idle, but it seems to have zero horse power. Any clues to my problems. Thanks!!! For looking. :)

[LakesOnly]

Not likely 460-specific and could be just about anything.
Since the motor starts and idles BUT has no power, AND sat for years, I'd suggest the first thing you should do is put a timing light on it and check your ignition timing...specifically, run the engine from idle to 3000 rpm while watching the timing marks on the front balancer, and verify that the advance mechanism isn't stuck after the boat sat for all those years. With the light on youre balancer, the timing light should show the marks advancing about 20 degrees or so (when revved from idle to 3000 rpm).
Also, since your crankcase was filled with gas, absolutely drain that out and start with fresh oil before you do anything else. The carburetor floats may be stuck, again from sitting bone dry for a few years and then being filled with fuel. And if the carb floats were stuck open when the boat was first stored in the first place, then fuel could have gravity fed past the floats, down the intake and into a cylinder with the open intake valve, and finally past the rings to the crankcase. Such a rich air/fuel mixture can also be the cause of lack of power.
There's tons more to address in regards to your symptoms, but let's start there and see what you observe from the analysis and checking. There will be others suggesting ideas too.
LO

[promod]

make sure that the power valve is at least a 6.5"

[Oldsquirt]

To add to what has been said....
A ruptured fuel pump diaphragm(mechanical pump) will not only dump fuel directly into the crankcase but will result in low flow/pressure to carb, potentially causing both of your symptoms.

[BRAWNY]

To add to what has been said....
A ruptured fuel pump diaphragm(mechanical pump) will not only dump fuel directly into the crankcase but will result in low flow/pressure to carb, potentially causing both of your symptoms.
had this problem and fixed it with a new fuel pump.

[1978 Rogers]

OK, I'm comfused. Does jbm have the problem or is Brawney just letting us know he fixed his problem.
In any case, I'd do what the other guys above me just said. YOu should be able to tell if the carb is floading by pull the sight plugs or looking in the window if you have the clear plastic plugs or look inside the carb and see if its still dumping fuel in after you stopped cranking it over.

[atxwrangler]

does the boat have a fuel regulator?my buddy washed out the bearings in his new motor because the builder did not put a fuel regulator on his motor.it didn,t take long at all, low oil pressure was the first thing he noticed!