In the FACTORY YAMAHA manual there is a section about the autolube oil injection system. In this section it tells you how to adjust the pump stroke and remove and install it. It also says the pump is a precision machined part and is unserviceable and if needed it should be replaced with a new pump. Well that was 40 years ago and the NOS pump supply has dried up. As you can see there are no less than 40 parts in this small pump. its about 2 inches square in size.
I forgot to bring my camera to take some pictures so we are reeling on the diagrams. I ordered a new seal kit fromlast week and it arrived yesterday. Kit comes with 3 oil seals 2 pump gaskets and some new screws. Theres not much info I have found about rebuilding these pumps on the interwebs.
I worked on this thing for a solid 4 hours and had it apart and together at least 15 times before I had it working where I was happy with it.
Last thing to do is bench test it with some oil and set the pump stroke for Idle conditions. Sorry again for the lack of pics today.