1974 18' Starcraft Holiday Aluminum Boat Restoration and Custom Build

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pckeen

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Re: 1974 18' Starcraft Holiday Aluminum Boat Restoration and Custom Build

Glad to hear you've been able to splash her. I have no idea what your boat is rated for now, in terms of HP, but I have an 18' Holiday - same hull design as yours, and it was rated for a 120hp, so it is possible that the 150hp is just too big for that boat. I run mine at about 38mph at WOT, with a 90 horse, and it runs fine. What is the height of your transom where the motor is mounted?
 
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pckeen

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Re: 1974 18' Starcraft Holiday Aluminum Boat Restoration and Custom Build

21" is still within the tolerances for a long shaft motor - so I would think that wouldn't be a problem. I'm thinking the issue is size of motor - your solution is simple - run it at about 35mph - at that speed, you'll do much better on gas.
 
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StickyHooks

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Re: 1974 18' Starcraft Holiday Aluminum Boat Restoration and Custom Build

I agree, 35mph is the sweet spot for both the hull and the engine rpm.

Tonight I had some time to pay close attention to the cavitation plate while on plane. The motor is mounted way too low as I have excess water above the cavitation plate while at speed. I'm thinking 2" higher would be perfect. Now the problem is how to raise it....this 1978 Mercury Black Max does not have adjustable mounting holes...

Does anyone make an adapter plate that will allow me to play with motor height? Powered jack plates are probably out of the question due to budget reasons.
 
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StickyHooks

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Re: 1974 18' Starcraft Holiday Aluminum Boat Restoration and Custom Build

After a quick ebay search it appears I can pick up a manual jack/set back plate for about 100$ (used).

Done deal. Will post back with results.
 
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