Topic: 78 Cb750 no oil pressure !!!! ideas? Please help.. I'm almost SO over this bike!

[timdhawk]

I have searched! 

I'm not getting oil pressure and I don't know why! I've tried priming the pump, I've leaned the bike over and put oil in the galley on the right side. With valve cover off, I've pored oil down the oil passages and I've taken my oil pump apart, checked all clearances, reassembled it (correctly) and its functioning as it should. Submerged in oil and rotating the drive gear I can see oil being pulled in and pushed out of the feed and return ports. With the oil pan off and the pump installed and bumping over the motor, I can see the drive gear spinning.
With valve cove off I'm not getting any oil up and with the oil filter off I'm not getting any oil out through there either... I'm using new 10W40 and I've spun the motor over 3-4 times for 10-20 seconds a time and no pressure on the gauge and the oil light stays on! (everything is well saturated with oil/lube)

- How much pressure is needed to actuate the oil leak stopper value on the pump?
- How much in and out free play movement should the drive gear have?
- What am I missing?
- What else can I check/do?

Thanx!

[ekpent]

 You may have to just fire it up once and get it started to really get the oil flowing. I know it sounds scary.  Think you had a post before but can't remember if you did a complete rebuild or what to your engine. If you watch inside the oil tank when you start it movement will happen quickly if all is good.

[Jerry Rxman Griffin aka MuthaF'er]

+1 Fire her up! It'll pop pressure probably within seconds.

[BomberMann650]

Is the pressure sensor wire connected ? 

+1 for run it and watch

[seanbarney41]

Are you sure you didn't leave out the oil jets that are under the cam towers in your cylinder head?

[Gene]

Are you sure you didn't leave out the oil jets that are under the cam towers in your cylinder head?

This seems to be a fair question. Posting just to see how it turns out.

[markreimer]

He’s not getting oil out the filter housing or side galley though. If those jets were gone I don’t think that would prevent the pump from pushing oil out to the filter, just wouldn’t build up pressure at the top right?


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[b52bombardier1]

Remove the valve caps over the adjusters and crank the engine vigorously with all spark plugs removed.  Shine a flashlight through one of these holes while cranking and see if you can view oil being pumped to the top of the head near the rockers.

Rick

[Patrick]

Did you do anything to the oil pump? They are really rugged and rarely break, but they are mechanical. The pump should have primed when you poured oil down the oil galley.

I've faced this with a few rebuilds. It is terrifying to start an engine you spend a ton of time and money on when you have no indication of oil flow. But eventually you have to bite the bullet. It is very difficult to build up oil pressure using just the starter or kicking the bike.

Whatever you do, do not start the engine with the galley plug or anything else removed from the engine - just to make sure of the flow. If you oil pump is working the oil will fly out at 60-80 pounds of pressure and make a huge mess.

Ten years and I still have the stains on my garage wall.

Patrick