JACK PLATES

[sea-hunter]

I am building a 20 ft tri hull with an 8 ft beam. I ant to use a used motor of about 80 hp to hold down costs. It is a planner hull but will only need to go arount 25 mph. The transom is 25 inches to the lowest point. The jack plates are 6 and 3/4 inches deep by 12 inches high and can be adjusted up and down 3 inches manually. <br />Questions. #1. At what height should I mount the plates. #2. What is the hole pattern for most engines? #3. Will this work okay? Thanks http://www.imagestation.com/album/?id=4292086811&idx=1 ]

 

[Dhadley]

Re: JACK PLATES

Neat project. There are a couple of other things we need to know. Are you going to use a 20" or 25" motor? A 3 blade or 4 blade prop? Have you run this boat before? If so in what configuration? Do you expect it to be a planing hull or stricly a displacement hull?<br /><br />The plates should mount to the boat using the standard ABYC bolt pattern. Most marinas have a drill fixture. If you don't want to buy one, just have someone drill the 4 holes. It can't cost that much. <br /><br />Good luck!

 

[sea-hunter]

Re: JACK PLATES

Had it in water as a catamaran last year running up to 10 mph with a 15 hp. After connecting the hulls the boat should have a draft of about 6 inches. Under power the front should come up and plane very easily. I'll probably get a long shaft. As far as props, I have no idea. Any suggestions? Thanks again.