To be honest, I've been avoiding messing with the filter head adjustment.
I just have a feeling that is not the answer like some of you guys said. Don't get me wrong, I would LOVE for it to be the answer, but I just don't think that will solve the real problem. As you know, this was an "in-frame" rebuild so I didn't take the crank shaft out. Nor did I plasti-gage the main journals.
Well, I talked to Chip and as always, he gave me more insight.
One thing he told me was adjusting the oil pump can sometimes cause more damage than good.
It could (in some cases) cause seals to leak or other little problems, etc. Instead, since there is a possibility of wear on the pump itself, like many of you suggested. A new oil pump is inexpensive and good insurance. Especially after everything done already.
About regrinding the crank shaft ...
He said he's not sure about how deep the heat treat on those Chinese crankshafts go? He would be concerned about that. He says they don't re-grind, they just put in a new one, because new crank shafts are so cheap. That's also why he doesn't stock under size connecting rod journal bearings. He would be afraid because he doesn't know how deep the case hardening is and it could be a problem if you grind through it.
I got to thinking about it and tend to agree with him.
I have worked enough times on this tractor to only to find that in some cases, the quality, finish and heat treat of their materials are just not up to USA standards. So taking into consideration what Chip said, I've decided to buy a new crank shaft, plus all new main and rod bearings too. I will be changing out ALL the bearings again, rod and mains etc. All new gaskets too. And a new oil pump as well.
The good news is he has a new crank in stock.
I say good news for me because that the whole shebang is:
1) very reasonable for everything shipped to my doorstep (under $700 for a new crank shaft, a new oil pump, all new gaskets and all new main and rod bearings)
2) I don't have to worry about finding a place to get it done
3) I don't have to worry about that case hardening (possible failure) or correct under sized rod bearings
4) I can do all the installation myself
5) It gives me another opportunity to bore you guys again.

6) Plus another learning opportunity about the bottom end of the motor, timing and all that.
So I don't have to rely on any outside service or guys.
Since the top end rebuild went pretty good, I've got a good feeling to match up the bottom end. I'll also have a chance to check and balance the pistons and connecting rods, if needed. Even check the roundness of the connecting rods where the bearings sit. I'll have all new bearings ... a complete rebuild and a brand new engine. Having chased down the air filter problem, it's possible I could get thousands of hours out of this rebuild.
I imagine the stuff will arrive in a week or so and I can start tearing the Kama apart again.
Happy New Year Guys!
Rob-