HELP! Can't do compression test on 76 Ford 351w |
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sberard5
Groupie Joined: August-31-2014 Location: Maine Status: Offline Points: 92 |
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Posted: October-14-2014 at 12:30pm |
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 |
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GottaSki
Grand Poobah Joined: April-21-2005 Location: NE CT Status: Offline Points: 3359 |
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Are all the spark plugs out?
What sort of battery are you using? Is your new starter the correct rotation? Your front pulleys should be spinning ccw. |
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"There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing."
River Rat to Mole |
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sberard5
Groupie Joined: August-31-2014 Location: Maine Status: Offline Points: 92 |
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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........ |
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21171 |
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Sounds like a battery problem, possibly exacerbated by corroded and/or undersized cables.
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sberard5
Groupie Joined: August-31-2014 Location: Maine Status: Offline Points: 92 |
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Engine is out of the boat. Using battery and jumper cables. Does turn over with the spark plugs in but struggles a little.
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Orlando76
Grand Poobah Joined: May-21-2013 Location: Mount Dora, FL Status: Offline Points: 3108 |
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I'd lose the jumper cables.
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GottaSki
Grand Poobah Joined: April-21-2005 Location: NE CT Status: Offline Points: 3359 |
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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. |
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"There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing."
River Rat to Mole |
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sberard5
Groupie Joined: August-31-2014 Location: Maine Status: Offline Points: 92 |
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Thanks for your advice. Problem is connecting my truck battery with side post terminals to the engine with the loop style battery cables. That is why I was using jumper cables. I'll see what I can come up with tomorrow. Any other hints greatly appreciated
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sberard5
Groupie Joined: August-31-2014 Location: Maine Status: Offline Points: 92 |
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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. |
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phatsat67
Grand Poobah Joined: March-13-2006 Location: Indiana Status: Offline Points: 6157 |
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Looks good as long as you have good oil pressure. Cold on a manual gauge it should pump up to at least 20 psi spinning with the plugs out.
The 240 hp Ford doesn't make enough power to hurt itself so as long as it has been somewhat maintained they are very robust with little issues and great reliability. |
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sberard5
Groupie Joined: August-31-2014 Location: Maine Status: Offline Points: 92 |
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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?
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Gary S
Grand Poobah Joined: November-30-2006 Location: Illinois Status: Offline Points: 14096 |
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Block circulation pump replace,raw water pump rebuild
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sberard5
Groupie Joined: August-31-2014 Location: Maine Status: Offline Points: 92 |
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Excellent. I am on it. Thanks
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41045 |
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Steve, You never mentioned if your leak is in the circ pump or the RWP. Which one is leaking? |
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