Yes, I have read many post about this, and instead of posting on each of them my findings and adventures, I am gonna start here.
Have 2006 Street Glide 88CID that ~48k miles ago I upgraded it to a stage 4 95CID. At that time, I went with the updated cam plate (25358-06) and updated oil pump (26277-06).
One night I rode her home, no issues. Next day she started puking oil out the air breather via the breather (vent) bolts from the head. This happens at 60-65mph in 5th gear. When it starts puking, the motor bogs down (not exactly sure why). While its puking, I pull in the clutch, the motor gets unbogged down (?) and all clears up and stays clear, as long as I dont get back in the problem area.

I have checked compression. Rear cyl was 155psi and held it for 10mins. Front cyl was 190psi and held for 10 mins. Then put .5 ounce oil in rear cyl and then got 190psi and it held for 10 mins. I think might be from carbon build up on front piston. However, with each cyl holding the psi, leads me to believe that there are no leaks in my rings or valves. I changed the umbrella valves and sponges in the rocker box. I took out the oil pump and notices some scarring on the scavenging side gerotors. I got a new pump and air breather (K&N), installed them, and get the same results. Today, after riding her back to the table, when I got there I opened my dip stick, and smoke came out. I started her with dip stick out, and more smoke came out. Not sure if this was exhaust or hot oil steam.

Until she starts puking and bogging down, she has great power.

I dont think the issue is the pump, though, as it doesnt seem to be an RPM generated problem. I think its more of a motor under load issue. On the table or kickstand, I can rev it up and hold and no puking occurs. Also opened up cam chest again to see if i missed or cut the big o-ring for scavenging, and everything inside looked fine.

Is there a way my rings are failing under load and causing excessive blow-by, causing the gases to push oil from the crank case up the push rod covers and out my breather?
Or what about a valve seal or gasket failing under load?

What do you guys think? Any suggestions on what to test next?

 

Time for a leak down test on both cylinders. Do not put oil in the cylinder as you did on the compression test. 150 psi dry and 190 w/oil on the rear cylinder tells me ring leakage...

 

First off, cylinders don't hold compression. Compression gauges do. Cylinders leak and you need a leak down tester for for that. Rear cylinder being low on the compression test but going up when oil is added (1/2 oz is a bit too much). means the rings are going.

Motor bogging down is a sure sign that it's sumping. When you replaced the pump, did you change the O ring in the case that the pump fits into?

You can try some sea foam in the intake, as you may have a sticking ring but the motor might need a top end.

Other things to check is crank runout. If it's excessive, the oil pump will have problems scavenging.

The bike is sumping. Sumping causes,

Too much oil pressure, Stuck pressure relief,
Hard case to pump o ring not sealing, (pump alignment)
Excessive cylinder leakage
Bad scavenge pump or something keeping it from doing it's job,
Stuck open, broken or loose piston oilers.

Valve seals won't cause it. It's possible that a headgasket might but the head dowel would have to be missing.

 

Now there is a million dollar thought. Never thought it was the gauge holding the max compression.

 

How is the oil level? Most run just under full to keep oil out of intake. If its puking alot of oil then sumping is going on.

 

Yes. Changed the three o-rings. One on the pump to crank channel, and 2 for inlet and outlet channels.

 

On cold it is near the bottom of full mark on dip stick. Always ran it this way.

 

Might be worthwhile to try running about 1/2 way down. It slows breather bleed but I doubt it will stop sumping.

 

Heres my problem. Cracked rear piston

 

Though break on that.. but at least you found the problem.. might as well bore to 98" and get this off the SE parts.. When you compare dollar to dollar Se/Indy, the Indy build will always out perform the SE...