Dave Cirkot,New Member, just bought 1974 18 foot hydrodyne ski boat, needs work Diamond in the rough

My first boat was a 76 with the 1st generation Mercury 175 - 1976. Yours looks more like a late 70's or early 80's 150. If you are new to Hydrodynes be careful of the fin when loading on that trailer without guide poles. Those cast aluminum fins are hard to come by. Will last you a lifetime if you keep water out of the transom.

 

How long has it been on that trailer if you know?

 

Trailer is a 1974, boat has 74 as the last 2 numbers in the HID, but it was listed for sale one time as a 77 by 2nd to last owner so not sure. Interested to know how to determine the year.
The motor is a 1987, so its not the original which I think was a 100 HP straight 6. The boat has been on the trailer since 2007 and only started once or twice by the previous owner which is a cousin. There was no fin nor were the holes ever used to mount it. I think I might make one with a Carbon fiber mold layup over the winter.
Floor has been removed, along with stringers and bulkheads. Transom feels solid and no wet wood thru the engine bolt holes but its coming out and Coosa 3 " going in as well as Coosa stringers and bulkheads and deck.

 

Trailer is a 1974, boat has 74 as the last 2 numbers in the HID, but it was listed for sale one time as a 77 by 2nd to last owner so not sure. Interested to know how to determine the year.
The motor is a 1987, so its not the original which I think was a 100 HP straight 6. The boat has been on the trailer since 2007 and only started once or twice by the previous owner which is a cousin. There was no fin nor were the holes ever used to mount it. I think I might make one with a Carbon fiber mold layup over the winter.
Floor has been removed, along with stringers and bulkheads. Transom feels solid and no wet wood thru the engine bolt holes but its coming out and Coosa 3 " going in as well as Coosa stringers and bulkheads and deck.

 

The boat looks to be in pretty good shape cosmetically.

Are the fin mounting holes sealed?

Is there a number stamped on the outer transom on the right side? if so, the last two numbers are the year.

I think it is clever how the inner rollers are set up to center the boat on the trailer. I had a boat with a trailer like that and the rollers actually dimpled the hull. The cored Dyne hull is pretty tough. I suggest that you might want to slide the boat back a couple inches and look at the hull.

If it were mine, I would either convert the trailer to bunks by removing the rollers and mount 2x6 bunks to those rockers, if they will match up to the hull. Or, get a suitable bunk trailer. If you convert that trailer, it will need some sort of centering device.

Mercury built a 2.5 liter 150,175,200 in the 90's that is a great and light motor, one of my favorites.

jim

 

I assume you are in the northeast?

 

Fin holes are sealed,looks like they have never been used. Think I might create a carbon graphite version.

Last two HID numbers are 74 so its a 74 thank you for the info on that.

Plan is to convert the rear supports to bunks roughly about 6-8 feet and to lower the boat on the trailer about 4 inches, but keep the front rollers for now. What's the best way to ensure centering, side bunks??

This will be the 2nd boat I have restored.
The first is a Wriedt Spoiler jet boat , supercharged, alcohol water injected, nitrous injected "Family boat" also used for skiing, but was looking for a more normal everyday dedicated ski boat.

 

Correct, where are you located?

 

side bunks ok. Posts at the rear better IMO. I am in Florida.