Re: 9.9 evinrude water intake tube length
If you're going from Extra long shaft (25) to short shaft (15), you take 10-inches off. If going from long shaft to short shaft, take 5-inches off. Make sure to "dull" the edges of the water tube so that it won't catch the grommet in the impeller housing. Some 220-grit sandpaper to round the edges works fine...
- Scott