Posted by HappyIdiot on 09/25/14 - 6:04 PM
#1
I have a 1989 merc 40hp on my 1985 15' super sport. I took it out for the first time tonight and found that it was porpoising with the trim almost all the way down. It did stop only after it was all the way down. The motor is mounted down as far as it can go on the transom. Can I improve performance if I move the motor up? If so how much? I'm running merc aluminum 10 1/2" 13 pitch prop. There are pics on my personal page. Thanks for any help.
Posted by wlagarde on 09/25/14 - 6:14 PM
#2
Yes - I had similar behavior with my 40 (before upgrading it to a 50). Raise the engine at least 2 holes up and if you can get away with 3 holes up even better. You can expect the porpoising to improve/resolve, your hole shot improve, and top end performance to improve. Also consider upgrading to a stainless prop. See here:
http://www.whalercentral.com/userphot...lbum_id=64
Posted by dougt on 09/25/14 - 7:26 PM
#3
Yep,
I just checked my Nephews relatively new15' Sport rigged by Boston Whaler.
He bought it new at the boat show.
He has a Mercury and it's mounted with 2 holes showing above bolts.