Seawater Impeller Change on Yanmar 4JH

[Moontide]

As I recall, the Yanmar service manual says take of the engine mount and then remove the whole pump body. Not sure why unless they want to run the hours up.
I can get the impeller out between the pump body and the back of the starter but it is very tight on the 3JH. Not enough room to use an impeller puller. I would think there is more room on the 4JH since you have an extra cylinder of length.

One trick to get new impeller in is to use tape or a zip tie to compress the blades before inserting.

Bill