How much HP with I/O to OB conversion

[1973Chieftain]

Good day! I am considering converting my 24' aluminum express cruiser from an i/o to an OB. How would I go about figuring what the max HP would be? I believe it had a recommended max HP of 240 with an i/o- would that be the same for an outboard on a bracket? I'm thinking of putting a 250 on it if possible.

 

[jbcurt00]

Look who washed up.......

Welcome back, nice to see ya around the old joint

Isnt a 250 Yammy what Jas bought for his? I know you asked for info @his topic, but for the Photobucket mess, he hasnt been on much....

Good luck w the swap

You could probably get 4 of my boats on your Chieftain Express w 4 OBs and still not have 250hp :facepalm:

 

[GA_Boater]

There is Coast Guard formula using length, beam and I think hull depth to calculate max HP. No idea if brackets would add or subtract from the calc.

 

[1973Chieftain]

Hey JB and GA! It's been awhile... the Chief has languished in the barn since the kids came along, but now that my eldest is starting to daily ask to go boating I need to get her running strong lol. Right now I've been taking her (she's 2 lol) out in a 16' utility with a 25 on the back.

Yes, Jas got a Yammie 250 for his big boat, it's hard to see with no pics anymore, but I'm thinking I'm going for the same idea he is. A bracket that has a full width swim deck and a mount for a large single. The I/O has just been too much of a pain