Oil pump blues

Ugh, most of what I touch goes wrong on Commandos. I had a new ebay oil pump that spun free and sucked my finger into hole or pushed them off just by finger spin once oil dribbled into ports and gears. Then noticed one of the 4 screws way loose. Hm. Maybe I'd been into pump prior and given up on it or just put off till years later. This would be maybe pump 5 attended to in 11 yrs so mixed em up.

Anywho opened up flushed out, gave the brass plate a half dozen strokes on a wide file, but not enough to remove the gear witness marks then screwed back confident ready to spend off for install. Happened to give it a last spin but could not turn by fingers no more. Put in vise and could turn it stiffly but didn't ease up much. Opened back up pensively d/t the weak slot head screws but didn't see anything trapped and soon as the screws slightly un-torque it spun free as expected just oil drag resistance. Only thing I could remove metal from would be steel cogs, but I can't believe I removed enough to hardly notice let along bind up.

While 1st apart I had no intention to remove the gears but they fell out. Is it possible they only go in facing one way, particularly the driven intake gear with the slots for the drive shaft? I've done other pumps and it takes a lot more sanding and filing to get some fiction resistance back in worn plate. What would Mrs Hudson do?

Steve, I'm a trifle concerned about your use of a "file" on this precision piece of machinery.
!!!!! The heart of your engine, it has to be said.

The instructions for oil pump handling mention a fine grade of wet-n-dry, and a piece of glass as backing (to get a smooth surface to work to).

Now go and do this, and report back.....

Mixing the gears doesn't sound like a good move either.
By a careful study of wear marks and patterns, they can usually be put back into the same place.
They need to go back in the same place, if you are trying to clamp it all together and something is even a fraction of a thou tight, no turnee oilpumpie...

Hi Steve,take care to fit the gears the right way : the small champher in the centre of the gears hole must go inwards.....

OH goody goody, Marin, I think you may have taught me another Norton lesion.
Bevel of cogs goes inward to case or no "turnee oilpumpie..." : )

I delayed cutting wood because of delay diddling pump with hands so cold hard to feel stuff. I've two more pumps on hand assembled to compare, one with cracked snout but likely good innards. I've done past pumps by the manual so pretty sure I barely messed with the brass surface filing but to burnish it flatter smoother.
No fire tonight but not hard freeze either, might not rest till flipping cogs to report back. Mood swings up again thanks.

Steve, yes, the bevel on the inner hole of the gears goes towards the inside like marinatlas says. I found that somewhere, but not in the Workshop Manual or Clymer, I wish I could find the link. I think it is important. It should be one of those things Norton owners need to know.

Dave
69S

Ok Now ya tell me but glad I asked. Its almost balmy out tonight and Peel can't progress until this part spend off, so out to it and see what happens. I just sorta nudge poor Trixie hanging from rathers, who should have no more mystery to deal with just assemble with a few engine parts arrive.

Yippie! I was hoping yo all knew what to do. I flipped the two inlet cogs to put bevel inward, nipped up tight and it spun as it should. Wrapped in rag and found a box so tomorrow out it goes to a real mechanic to fit in Peel and test the cam clearances and its drive workings.

With this uplift in mood and mild evening might as well use it up trying to snip and bend the wire clips that hold headlight ring and reflector on Trixie. Needed hand holding on that too earlier.