Can I replace a short shaft with a long shaft motor?

[ridiver]

We recently purchased a boat that has a short shaft 85 Hp and would like to place our newer long shaft 120 Hp on it. Other than the motor sitting deeper in the water, are there any concerns? <br /><br />Thanks<br /><br /><br />PS: boat rated to 145 Hp

 

[grandx]

Re: Can I replace a short shaft with a long shaft motor?

Assuming short shaft is mounted properly, the long shaft motor should be lifted higher so that the cavitation plates are level with the bottom of the boat (+/- 1") or so, for best performance. Most outboards have a series of holes for mounting adjustments etc. The long shaft will push the boat, but will probably handle better at the right height.