Repowering 1972 18' Starcraft SS Advice

[Yotadude83]

Hi All,

Im hoping to get some kind of input on this as my mind keeps wondering if im making the right decision. I bought this 1972 Starcraft 18' SuperSport last year, the original owner bought it new and owned it all its life until he passed. When i got it home i started working on the engine but havent ever got it to work well, im tired of messing with a 51 year old engine at this point. My plan is to repower it with a newish 90hp Yamaha. I was out doing some work on it other day and checking out the transom and noticed the floor was rotten in one area...so i ripped out all the old wood, scrubbed and pressure washed the bottom of the boat. Everything looks fine to my eye no loose rivets that i could tell and only one spot that had a little bit of corrosion near the back, but it could also be because of some mud and old sparkplugs that were all stuck together down by the bilge pump. Anyway i will attach some pictures im kinda just looking for opinions, any red flags you see that would or should prevent me from going any further on this boat. Ive already replaced most of the foam in the boat, ive also finshed the floor with 1/2 marine grade plywood covered in epoxy. The boat appears to be in really good shape from what i heard the guy was really anal about his stuff, theres not a single rip or tear in any of the seats or vinyl, im kinda the same way im just hoping this boat is worth repowering so it would last me a few years, im not looking to keep it 10 years just looking to repower it so it would be more reliable and i can take that engine on to my next boat. Thanks!

 

[matt167]

I wouldn’t power it with less than 120hp. Not 100% sure on what it’s rated for but 90% sure it’s rated for at least 120hp. I have your boats close cousin, a 1971 Offshore V 18. But mines an I/O and now it’s got a 3.0L Alpha one

 

[Yotadude83]

I wouldn’t power it with less than 120hp. Not 100% sure on what it’s rated for but 90% sure it’s rated for at least 120hp. I have your boats close cousin, a 1971 Offshore V 18. But mines an I/O and now it’s got a 3.0L Alpha one

The plate on the boat says it’s good for 140hp. It currently has a Johnson 115 on it.

 

[matt167]

The plate on the boat says it’s good for 140hp. It currently has a Johnson 115 on it.

That’s a logical and adequate motor for the era.

 

[Rasdiir]

If the floor was bad I would check the transom wood too, especially if you will be putting a new, heavy, 4 stroke on there, but if there are no leaks then I would say it's worth it. That boat is in great shape, and looks like a quicker turn around on your repair then a lot of us here!

 

[Watermann]

Welcome to the fray! I would inspect the rib ends for any cracks since that era has no hull braces and if used with compromised decking it could have started the cracking. Chances are your good for cracking if it sat and got rotten and being an OB as well.

Only red flag I see is in the pic with the caulk gun not knowing what the sealer material is and when you're squirting it.

 

[Yotadude83]

Welcome to the fray! I would inspect the rib ends for any cracks since that era has no hull braces and if used with compromised decking it could have started the cracking. Chances are your good for cracking if it sat and got rotten and being an OB as well.

Only red flag I see is in the pic with the caulk gun not knowing what the sealer material is and when you're squirting it.

Sorry i thought i replied but i did a new post lol oops

Thanks! Sorry i didnt see this sooner, i dont remember seeing any cracks when i had everything apart the ONLY crack or split i found is up on the knee brace , it has one crack by the first bolt hole. Other than that i pretty much inspected everything and lol the caulk gun was for my own sanity i dont know if it did any good but i figured i would put a dollap of marine goop on each rivet on the boat....so i touched every rivet which was fun. The boat was kept under a cover all its life the only rotted area was in the back by the transom...the splashwell seal by the transom had worn apart and let a bunch of water and gas/oil mix in. Im going to replace the transom next as finally was able to remove the engine. The floor was half newish half old someone did a repair somepoint in its life.

 

[Yotadude83]

If the floor was bad I would check the transom wood too, especially if you will be putting a new, heavy, 4 stroke on there, but if there are no leaks then I would say it's worth it. That boat is in great shape, and looks like a quicker turn around on your repair then a lot of us here!

thanks yea im pretty sure 90 percent of that water damage was from water coming in from the unsealed splash well and running down into the floor.
I wasnt going to replace the transom until last night when i told my self you would be an idiot not to replace it cause i have everything in the back removed and i pulled the engine so theres only a few bolts left to remove. So fingers crossed it comes out easy. I think the original owner just got too old to do some of the repairs and let it sit for the last 2 years before i got it.It was just sopposed to be a starter boat to see if i like boating but hey i been really enjoying fixing it and i cant wait to take it out fishing. Im not 100 percent on the leaking i did go and put sealant on every rivet inside the boat, i have a kicker motor im very tempted to toss on and take for a spin, the lake is only a mile from me.