1987 40ETLH Oil Pump Change Out Question

[Bullbream]

I've been wanting to try replacing my oil pump for a while, but I'm unsure about which part number is correct. It is slow to send oil up to the top cylinder of my 3 cyl. outboard. I watch the clear oil lines at idle and it just creeps up to the top cylinder, doesn't really start flowing til you get it off idle. as a result I have usually mixed my fuel 100:1 just in case its failing. When I look at the part numbers online I see the original Yamaha number is 6H4-13200-01-00. However, some sites show this has been superceded to a 6H4-W1320-09-00. And the pictures of this appear quite a bit different than my pump. The first pic shows my original pump as installed with the 3 oil injection lines all in a row. The second pic is from shots I have seen online of the "newer" style. The 3rd oil injection line seems to be in a different location. Does anyone have any experience with these 40HP injection pumps. Does the newer style give better output? Thanks much in advance!
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[boscoe99]

At idle the oil pump is only outputting enough oil for a 200/1 mix. The motor at idle is using so little gasoline that I am surprised that you can measure any oil flow at all.

Why did you not follow the service manual procedure for testing the output of the oil pump?

Pump part number 6H4-13200-01-00 has been replaced by pump part number 6H4-W1320-09-00.

[boscoe99]

What does "give better output" mean? More oil? I don't think so.

[99yam40]

seems like I remember something about one pump having internal check valves, and the other having in line check valves.
the check valves are to Keep the oil from draining back out of the lines once primed.
could that be one of your problems on #1 cylinder