It looks like this guy may have an electronic magneto fitted to it.
This engine apparently has a straight shaft. The slotted pump input slides over the output shaft and is held in place with a clamp.
Currently I am working on getting the pump to slide off the motor output shaft. It is slow going, maybe splitting the pump will help.
It came off after splitting the pump. A 15/16th inch socket on the impeller nut with an air impact loosened the slotted sleeve over the output shaft. The good news is that this is the first engine to have a standard non-tapered shaft with a keyway.
I used a vice grip as a fork to lift the valve out of the guide.
The valve is worn on one side by about 3/1000th.
The stem was further damaged the guide as you can see by the brass on my finger. For now this engine goes on the shelf.