1970 Jet Star repower and transom replacement

[Vtstar]

The old Merc 650 on my Jet Star finally got the better of me and fixing it was just not in the cards for me. Plus as fun as 65 horses were on this boat, 50 is more appropriate and will be a bit less stern heavy. Plus, the transom was hacked down to accommodate the shorter shaft. Overall probably not the best scenario.

so out with the old...

Hacked transom

oh yeah, turns out there were no through bolts holding this beast on. Clamps and gravity took care of that.

then out with the old transom, pity though as it was still quite solid for being the original

Pull!!

Free at last

So.... need to address the cutout section of aluminum. New board is cut and glued and undergoing spar treatment. Just trying to figure out the best way to cover and protect the area that was cut out.

 

[Vtstar]

And the new board cut, glued and shaped. Fits right in but now straight across.

This is like one of those cooking shows where they just pull the finished product out of the oven. In reality, it took quite some time to yank the thing out. I found a phantom screw that certainly held me back. I also drilled, hacked, chiseled, etc to get the darn thing out. I did manage to keep the splashwell in the boat. I know this makes it a bit harder but I was glad i did not have to remove it. The new transom slides in just fine.

 

[Nismoron]

MAN!! You work fast! I need to get you over here to help pull mine out! Unfortunately, my splash well HAS to come out.
So, what is going back on? A 50hp what?

 

[Watermann]

Ouch the transom hack job once again and to such a nice little boat from what I can see in the stern pics that is. First off clean that inside and outside AL transom skin down to bare and see how much pitting needs repaired. I hope your planning on upgrading to a different helm too to get away from the cable set up.

 

[Vtstar]

So I have a 50hp twin cylinder going on the back of the jet star. Should push it just fine. For som reason I kind of like the old cable and pulley system so I am going to keep it. I like the old school steering wheel and the retro look and feel. I will replace the cable though.

 

[jbcurt00]

Welcome to the Tin-sanity. Great project

 

[Vtstar]

It's funny how one thing can lead to another. The 1970 vintage Holsclaw trailer was looking a bit beat up, something that bothered me since i painted the boat. I figured while the boat was sans motor, it was a good time to spruce up the trailer. Not a full rebuild or anything, the trailer is quite functional, just has surface rust, dings, etc. I hit it with a wire brush, primed and painted it. Black and white was simple and improves the look quite a bit. Close inspection certainly shows its age but black tends to hide most of that.

Old trailer, would rather have the eye drawn to the boat

Off she goes up on blocks, my way of classing up the neighborhood

Primer (guess the tilt works, never used it)

And Paint, much better

 

[jbcurt00]

Looks good. Nice work

 

[classiccat]

Very fitting carriage for that sweet tinnie!

 

[Vtstar]

So back to the task at hand, transom replacement.... I have a question about towing ring placement. Should I go out to the back corners of the boat through the middle bolt? (red line/arrow in the pic) or should I go to the outside hole of where the handles were mounted with a large backing plate (green arrow) ?

I am inclined to use the outside middle bolt. It means one less hole and there is a corner bracket inside that would provide good backing support. This is unless there is some reason extra stress should not be put on this part of the boat. I have seen both ways here, just curious what others have to say.

 

[snowman48047]

Only thing I can think of is none came from the factory with eyes that far outboard. That I know of....

 

[Watermann]

So back to the task at hand, transom replacement.... I have a question about towing ring placement. Should I go out to the back corners of the boat through the middle bolt? (red line/arrow in the pic) or should I go to the outside hole of where the handles were mounted with a large backing plate (green arrow) ?

I am inclined to use the outside middle bolt. It means one less hole and there is a corner bracket inside that would provide good backing support. This is unless there is some reason extra stress should not be put on this part of the boat. I have seen both ways here, just curious what others have to say.

What in the heck, that's a single eye in the stern like used to hang flower pots. I would go from that eye as to only make one more hole and with some actual 3/8" SS stern eyes. I would not drill holes at the outer edge of the transom through the side bracket for one no boat manufacturers do that when installing stern eyes, they are always further inboard.

 

[Vtstar]

That actually is a 3/8 SS eye with a 3 inch backing plate. Are you saying to use the ones that mount flush vs the hardware store variety? Either way it sounds like mounting out on the edges would not be ideal. Probably other forces are acting on those corner braces such that they should probably be left alone.

 

[Watermann]

Yeah I was talking about these.

http://www.iboats.com/Seachoice-Bow...480667500--session_id.294418241--view_id.2968

 

[Vtstar]

Those do look better than the single eye. I will look for something like that locally. Back on the project, I filled in the hacked transom:

Found a good piece of metal to do it with:

I will also use some of this for the transom cap as we'll. I am securing the patched piece in with JB weld. That should be ok since the structure is in the wood, not the aluminum skin. Please correct me if I am wrong here.

 

[Watermann]

The only problem I can for see is when you tighten the motor mount bolts though and the different rate the bolts get tightened could cause the JB seam to snap which would suck after painting. You're right though it is just a skin but I think you should put an outer AL piece over that patch, it could be a motor pad sized one that covers most of the patch and replaces the wood one you can see the outline of still. That would add strength to the patch as well as cover and seal the old motor mount holes that won't line up to the new motor location.

 

[Vtstar]

Some progress. I used another piece of the stop sign to cover the patch.

My original plan was to bend the added piece right over the top of the transom to have a one-piece cap but that metal was next to impossible for me to bend. I clamped, pounded the #^%! out of it but in the end I am opting for overlapping L-Channel to finish it off.

 

[lakelover]

The channel will work fine, you're right, those are just about bend-proof unless you demolish one with a car! I don't know what metal they're made from, but you don't usually see them rusting either.

 

[Watermann]

Looks good from here! :thumb:

Those highway signs are normally .080 5052 AL good stuff for making patches and even hull stiffeners too.

 

[Vtstar]

I didn't mean to leave folks hanging but the repower did get completed. I will catch you up on the rest of the project. These pics are from last Sept....

After the transom install and the stop sign repair to the butchered aluminum (see prior posts), I had to fabricate a holder for the motor controls:


Then on went the new (old) motor:


50 horses of pure US Marine power. Price was right and it should get the job done


More to come....