I spent an inordinate amount of time on the primer and oil pump(s) yesterday.
On the primer, I tapped the plunger 8-32 and use my old cheapo WalMart slide hammer to pull the pump apart. This is the orientation of the primer on the saw, fuel enters the lower port (red) and is pushed up into the carburetor (red port) when the spring returns the plunger. The cup seal is 24104 and the o-ring is a 010. I was able to reuse the felt seal/packing, the ring holds the felt in place.
It is important to get the gland pressed back into the proper position so I made a little guide from a piece of tubing I had on hand. If you look carefully you can see the groove and the hole in the gland aligned with the outlet port.
These is another disk with a hole and a small check ball at the very bottom of the primer but I did not have to remove them on this one.
The manual oil pump is a pretty simple affair.
If you press the plug on the end the pin will come out releasing the plug.
At that point the whole plunger can be pushed out.
Again, the o-ring is a 010 and the cup seal is 24104.
To access the felt seal/packing in the other end of the pump you have to remove the washer. On some, the stake marks are pretty light and you can just pry it out. On others it may be necessary to drive a bit of material back from the edges.
Here you can see the felt seal/packing and washer, there is also a 010 o-ring at the bottom of the gland.
Apparently I forgot to take any photos but I replaced the felt with bushing made from UHMW PE with an o-ring on either end.
Good news is with new cup seals installed, the oil pump is working. Bad news was the original oil pump from this saw (brass plunger in the photos) was so badly worn I had to rebuild a second pump from a parts saw on hand to be sure the rod that drives the pump won't fall out...
Mark
