Shaft Extension

[Reel Kahuna]

I've got an F150 20" shaft with less than 300 hrs and want to buy the extension to convert it to a 25" shaft and mount it on another boat. Has anyone done this and if so, any issues?

[boats.net]

Yamaha doesn't offer shaft extension kits, would have to check to see if any aftermarket company's offer one.

[99yam40]

I've got an F150 20" shaft with less than 300 hrs and want to buy the extension to convert it to a 25" shaft and mount it on another boat. Has anyone done this and if so, any issues?

You do realize the drive shaft and water tube along with a case extension will be required. That means either opening up the lower unit to swap shafts or a different lower unit and pulling power head to change tube.
Do a web search for a after market shaft extension

Here is one OUTBOARD LONG SHAFT EXTENSION KITS