no oil pressure

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drewmaster

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I have a 1975 viking deck boat with a OMC 140 stern drive(model#990226A1)(serial#W482397). It has been sitting for at least two years, just got it started and there is no oil pumping up the push rods and no pressure registering on the guage. The oil pump has lost its prime or is bad and needs replaced I am assuming. Are there any tricks to get this oil pump pumping oil again short of pulling the engine out of the boat to replace the oil pump?
 
matt167

matt167

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Re: no oil pressure

The oil pump drives from the end of the distributor, so all you do is pull it out, chuck in your oil pump primer into a drill and turn it forward.. I 'think' a SBC primer adapter will work but I'm not 100% sure, an old like distributor shaft will certinly work. If you ran it too long with no pressure the bearings are wiped and it does not matter anyway.
 
tazrig

tazrig

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Re: no oil pressure

Remember to put matching marks on both your distributer and the block with a sharpie marker and note the orientation of the inner shaft (under the distributer cap) so you won't have to start from scratch with your timing when you re-install it. You should be able to get a pump primer at just about any auto parts store if you don't already have one for real cheap money. Just looks like a long flat screwdriver with a circle around the head to keep it on the pump when spinning it with the drill.
 
D

drewmaster

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Re: no oil pressure

Forgot to say we tried that already and then changed the oil too and nothing... not looking good, huh? Thank you guys for such a rapid response. Any other ideas are most welcome. Drewmaster:)
 
matt167

matt167

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Re: no oil pressure

Probably a clogged pickup or it fell off and dropped into the pan. If Either happened, it probably happened while running and at the very least, need new bearings. Oil pump should self prime anyway, and unless it's physically broken it should still work, even totally worn out those gears can still pump some
 
D

drewmaster

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Re: no oil pressure

You know your stuff Matt, pulled the motor and pan- pickup laying in the bottom of the pan. It was bolted in place and had snapped off from vibration! The bearings look ok, not great, but ok. I sure don't want to rebuild the whole bottom end this year, I wont get on the lake until December. Thank you for the great info and ideas Im sure I will need more help later. Drewmaster
 
matt167

matt167

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Re: no oil pressure

If the bearings are showing any copper but the crank is still ok just stick some new one's in. It can be done with the crank in, and it's pretty easy if the motors upside down on a stand. Make sure you match stock or undersize, and you can plastigauge or mic it to be sure. That will make it last for at least the season. Also, use some thick assembly lube when you put it back togther. STP in the blue bottle will work.
 
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drewmaster

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Re: no oil pressure

We are talking about rod bearings right? I can switch the rod bearings(4) no problem but the main bearings(5) would be much harder, it looks like to me. Drewmaster
 
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howlnmad

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Jul 29, 2009
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Re: no oil pressure

drewmaster said:
We are talking about rod bearings right? I can switch the rod bearings(4) no problem but the main bearings(5) would be much harder, it looks like to me. Drewmaster
Click to expand...

If you have the pan off, it's no big deal to roll out and in new mains.
 
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