2006 Yamaha F150 TXR, new question

[Jackofalltrades]

First, thanks for all the help this group provided to help me understand and resolve the oil pressure/leak issue I was having. I have finally resolved "that" problem and have great oil pressure but now I have a knock at low RPMs (from Idle up to about 2400 RPMs), then it quietens down. While I was trying to figure out this oil pressure/oil leak problem, I got the low pressure alarm and had to shut the engine down a few times but never let it run more than 5 seconds.
The problems I found were, a damaged main seal at the bottom of the power head, and a damaged oil pump. I replaced the pump, main seal, and installed a speedi sleeve on the output shaft.

Now there is great oil pressure (installed a gauge at the oil pressure sensor so I Can see it)... there are zero oil leaks and everything sounded perfect when I ran it on the water, for about a minute, then it started knocking at RPMs. It sounds like someone is lightly tapping on the harmonic balancer with a hammer from the inside. So I'm guessing its self inflicted heat/friction damage, due to lack of lubrication that has caused something to fail/partially fail.

I know I am going to have to get in there and look. Just thought the experts may be able to tell me what to expect to need to repair/replace and, or what to look for when I get in there. What are the likely suspects?

[Bluefish]

If you suspect the balancer, I would not run the engine anymore! It’s easy to take off and check. They have done a few design changes on the balancer over the years. Do a search for the balancer people describe the sound differently. You don’t want the plastic from the gears getting into the oil system after just getting it repaired.

[Jackofalltrades]

Thank you Bluefish. Yep, I actually just replaced the harmonic balancer, oil pump, seals and went through the process of cleaning out the entire system. Yuck and you are right, I dont want to lost and new parts if I can avoid it!. Ill pull the HB and have a look.