Bad Oil Pump?

[cr55]

Hey everyone, I'm a newbe on this site and I looked around quite a bit elsewhere before joining here. I have a tech question. I have a 48 pan with the original oil pump. It lets all the oil in the tank flow thru to the primary and leak out in about 2 or 3 days of sitting. I've changed the balls in the pump, but still does the same and last time I rode the bike it started loosing oil pressure after about 40 minutes. The screw that limits the oil flow to the primary chain has broken off also. Do you think I should try to find a rebuild kit for the pump or change to a later model style? I've heard both sides of the new pump install. Some say you have to drill with a jig and others say you don't! What are your thoughts?...Thanks, CR

[NightShift]

Dear cr55,
Even perfect pumps dont pump the same pressure to a hot motor as cold because pressures got nothing to do with it anyway.
If you got a gauge dont look at it.

A James gasket kit is great but youll need a new check ball spring and a new primary oiler screw and anything else broken.
And a cam cover gasket probably.

Two or three days is awful fast. Even bad sumpers take a couple of weeks.
You didn't set the ball with a punch did you?

Had to ask,
Respectably,

[cr55]

No I didn't set the ball with a punch. The pump has gotten worse through out the years to where it will drop all of the oil within a few days and the pressure went from a high of 40lbs in the beginning to a low of 0lbs in a short time....CR

[Cotten]

CR!

Pressure readings tell little or nothing about the pump.
The fall in apparent pressure results from the expansion of motor clearances, and thinning of the oil, from heat.

High pressure upon start-up is a result of restricted flow: The motor is not getting all the oil it should.
When warmed, the oil can gush through, and the pressure drops off.

So, your motor has loosened up over the years. That's all a gauge tells you.

If you feel your pump itself is worn, then an inspection of clearances will tell if the casting should be ground to take up side slop, or perhaps even gear replacement.

Your rate of sumping is enormous.
And once again, your pressure observations have nothing to do with the check valve.
I can only suggest careful observation when dis-assembling, as you may find a breached gasket, or perhaps a foreign object obstructing the ball.
Seats can be re-conditioned; please type "burnisher" into the search function.

Good luck,

....Cotten

[cr55]

I looked up burnishing through the search, but I'm not real clear on what that does or how to do it....CR

[panhead]

Check the KB: Sumping Blues

[cr55]

Guys, thanks for all the help. I'll try the burnishing trick when I get a chance, hopefully it'll do the trick!...CR