No oil getting to top end after rebuild (careful rebuild)

Gents,
I'm back from the dead. Long story short, about six months ago oil stopped getting to my top end on my 71 CB350 K3, I was able to catch it before too much damage was done.. although it did destroy my cam and my point cover. (I have pics if you want to see the destruction). But now it appears I am back in the same place.

During my rebuild, I took the opportunity to bore out the cylinders (because I was getting blow by & white smoke out the breather tube) and paint the engine.

After dealing with idiots boring out my engine (supposed to do a .50 over...instead did a 1.0 over) I got back to assembling the engine. (Using compressed air) I blew out all the oil routes when piecing the girl back together. All of them seemed clear. I cleaned the oil pump and the screen. Then when I kicked the engine over, and it started up nice & loud. The first thing i checked was the oil hole on the top left side of the engine. No oil was coming out so stuck a thin paper towel in there & it cam out clean. (I had the engine at 4k RPM). At this point, I shed a tear & shut down the engine before I offered another destroyed cam to the cafe-gods.

What are my potential problems and what are my potential solutions? I've never heard of a failed oil pump on a cb350, but is this a possibility? I should be able to leave the engine on the frame and take off the right engine cover to pull it & inspect it & if need be replace it? Beyond that, the only thing that coming to mind is that somehow one of the oil routes is blocked.

I'm open any ideas...

I'm going to go chug some whiskey.


-cfogs

did you clean out the centrifugal trap ?
did you put the gaskets for the cam blocks in correctly ?

When it was apart, did you remove the clutch cover and inspect the pump and did you flush out all the oilways to the bottom end and top end. Most likely issues:
Blocked oilway.
damaged oil pump dirt on screen or ball valves stuck open or closed.

How did your machine shop screw that up? They matched the bore to the pistons you supplied - yes?

Did you have the rubber ball in the lower crankcase oil passageway? Mine was missing on the motor I torn down because of the same oil starvation problems. Not sure how much it really matters, but Honda put it in there for some reason.

I'll be removing the Right Crank Case Cover to do some investigating... I should be able to use compressed air to see an oil way is blocked when the right crankcase cover is removed by shooting air into the oil holes. But to remove the pump I'll need to borrow that wrench. Last time I took it to a shop an borrowed theirs on-site. The people are pretty cool & will let me probably bring it home for the morning to get it off.

When it was apart, I did clean the screen, and inspect the oil pump. Nothing seemed out of the ordinary. Is there actually a way to test the oil pump?

When its apart, I'll give a look for that rubber ball....I'm trying to remember if I saw one when I tore it apart...the memory currently escapes me.

Wish me luck.

Pictures included.

Update:
Okay, So I pulled off both the left and crank case cover and blew into the holes that run along the top of the crank case. I had good air flow in between them, however, I barely felt any air coming out of the top hole of the left side of the cam-case. I even tried blocking one of the holes to try and force more air up the "engine-rods." However, that didn't change the symptoms being experienced on the top end of the engine.

Would I be right to assume that there is some blockage in the top end in the oil's ascension to the cam case? That would seem logical to me.

My next step is to dismount the engine. Break down the top half. and blow air in those holes and see where it's getting stuck.

Wish me luck...I'll be at it all night.

attached are some photos to show you what I'm looking at.

Appreciate any input

Here are the pictures with the oil holes highlighted.

...& one more

I usually remove or loosen the two acorn nuts on the two outer rear studs and spin the motor over (side covers ON) to see if oil is coming up the studs. You may have a blockage in the cam towers or the cam tower gaskets.

Re: No oil getting to top end after rebuild (careful rebuild) (fixed)

Hey boys,
Good news. I went back through and cleaned out all the oil holes. It appears a little lock tight somehow found its way into the lower right hole on the upper crank case (where it goes up to the cam housing). I blew everything out before...but it looked like the air was barely getting by so I didn't detect it.
She's all just about put back together. I'm having some odd issues with the Gear Shift Drum Guide Ball & Spring. I've messed with it a few times, but it keeps seeming to bind the shifting process. I'm going to keep trouble shooting & see what we get!
Thanks the help!