HELP! Can't do compression test on 76 Ford 351w

Excellent. I am on it. Thanks

Great thanks. I will continue on. Did find that the pump seal on the engine water pump is leaking. I take it they aren't rebuildable anymore? Easier to replace?

UPDATE!

Took your advice and took battery out of my 06 GMC pickup. Using battery cables and a disconnect switch to make/break starter connection. Hooked everything up and tried. Turns over much faster now. Now onto the compression test.

Squirted about 1-2 tablespoons into each cylinder prior to doing test.
Here are my results. Note: Engine removed from boat so these are cold test numbers.

1-130    5-125
2-120    6-150
3-130    7-120
4-130    8-145

From what I have read these numbers look good. Anything I should be concerned about? Thanks again guys for your help. Much appreciated.

I concur, jumper cables are not helping.

A Deep cell 500AH battery is crap even when new, they are made for electric fish motors and outboards.

Take a real starting battery out of your truck and spin it.

Engine is out of the boat. Using battery and jumper cables. Does turn over with the spark plugs in but struggles a little.

Spark plugs are out, carburator removed and intake wide open

Battery is out of my other boat.
Deep cell marine 500 Cold Cranking Amps, 625 Marine Cranking amps.

Starter seems to be correct rotation, front pulleys spinning ccw.

Also note, I have removed the transmission as well........

I recently picked up a 76 Ski Nautique as a winter project. It has a Ford 351w and it is removed from the boat for stringer repairs. I am trying to do a compression test on the motor to see if I can get a year or two out of it before tearing down and have run into a problem.

Problem is: I cannot get the engine to spin over fast enough to do a test. It doesn't seem to spin as freely as it should. Unsure of when the last time the motor ran but it was winterized when stored.

Here is what I have done so far:

Marvel mystery oil in the cylinders as well as some 10w30
Installed new starter
Removed belts
Marked and removed distributer
Changed engine oil and filter (old oil was thick and black and sludgy)
Primed oil pump - Thats where I stopped. Using a drill and a 5/16" socket and extension, I attempted to prime the oil pump in the LH direction same direction as the crank pulley. I verified it is the correct direction. I am just barely able to get oil to a few of the rockers but the drill slows down and stops. Too much resistance. Not sure where to go from here.

Has anyone run into this on an engine that has sat a while. I figured with fresh oil and filter and primed pump I would get the engine to spin freely. I am baffled. Did notice that the compression was higher after doing all of this work but motor still spins slowly.

Please Help. Best way to get ahold of me is my email sberard@myottmail.com or PM me.

thanks in advance