1986 Scarab II 29’ resto
 

Long time reader relatively new poster. After salivating over this forum for a decade, I finally bought a “go-fast” boat: 1986 scarab II 29’.

I paid $10k for it with a trailer. I got it from a good friend I’ve known for decades. He didn’t want to take care of it anymore. It runs & drives (72mph), but it needs work.

Supposedly, the transom and stringers were redone with COOSABOARD in 2017. The engines are ~450hp 454s built by BOWERS marine in NC. It has 10 hours since its 2017 restoration. It has TRS Drives in good running condition. Rebuild status and hours are unknown. I have no way of verifying all this info, but I trust my friend who sold it to me. I’ve ridden on the boat and helped him maintain it over the years.

The electrical wiring is a mess and most gauges don’t work. The cockpit and cabin are faded and could really use new upholstery. I plan to fix all this myself.

I’d like to put in AUTOMETER marine or some other type of modern gauges. I’d like to ditch the teak wood and modernize the cockpit. If “resto-mod” the boat, am I committing blasphemy and ruining its value?

can anyone recommend some reading material or websites/blogs for me to get smarter on this boat? I’ve restored cars, but not a boat.

I am in the middle of that same type of restoration. Sad thing about Scarabs is they don't hold the value of a Cigarette or Donzi, so if you restore it to "original" it won't be worth what you spent, and it'll perform like a 1986 boat.

If you resto-rod it, it'll look and feel more modern, be what you want it to be, do what you want it to do, and that way you can at least justify the money spent. Still won't be 'worth' what you spent, but you'll enjoy it a whole bunch more and most casual observers won't know how old it is. You'll at least get to enjoy the money you spent your way! That's what I tell my wife anyway!!! LOL!

Yeah that was my thought as well. If I replace the gauges & switches, put in new upholstery, and ditch the teak for some fiberglass panels, it’ll look 15-20 years newer.

I’m pretty sure I could sell the motors, drives, and trailer & get more than my money back if I so choose.

I intend to use this as a family/dogs boat and the occasional poker runner.

There have been a lot of resto-mods threads/projects posted over the years, all too often there is a flurry of activity and then...nothing from the o.p., but the ones that DO make it are often quite nice. New Livorsi, Gaffrig or even Faria gauges will make a difference, but you could go for a full 'glass cockpit' with a couple of Garmin units to REALLY modernize it. Upholstery makes a HUGE difference as you note. Going with some carbon fiber or faux carbon fiber touches in strategic places enhances that modern feel. Sounds like the engines and drives are strong and won't need work, so that frees up some $$$$ to do other things. A ten or twenty thousand dollar investment in that boat would really make it stand out in the crowd, if that is your thing.

I don’t have a desire to do a “build thread”. I’m more looking for ideas. Glass cockpit sounds expensive.
I forgot about Faria gauges. Those are probably cheaper than autometer. I priced out all the auto meter gauges I want and it was like $1600.

I freakin love the carbon fiber idea. I never would have thought of that.

keep the good ideas rolling. I’ll post pics soon

I actually added all the missing teak back to my 77 mirage I’ve been restomoding. But I am trying to stay with a classic look.
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All my teak is going. Have a new interior being done. I went with Autometer Prolite Marine, polished with candy orange bezels, new paint, new fittings, recessed cleats, taking off the front rail and smoothing the deck. Aluminum platform instead of the teak, all led lights. Twin turboing the 454s with Kaama surface drives. I think it will be nice when done. Look newer, feel new, still make a statement when you pull up.

Nice project...good on you to take it on.

Upholstery is my Nemesis.

Can anyone post a link or video about fluid change and servicing the transmission? I know this thing has either MERCTRANS or VELVETDRIVES in it. I’m unsure how to tell which one and how to service it. Google, forum, and YouTube searches don’t have much. That’s understandable considering these were obsolete before the internet was invented.

Its 110* in the Mojave desert where I live, so I’m not gonna start tearing into this project till it cools down a little.

The Merctrans II was what Merc Initially used...then went with the Velvet Drive in the 80s. Not sure when the transition happened.
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Merctrans are more compact and keep the engine closer to the transom by about 6-7" compared to Velvet Drive.
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There is some Merc service manuals available...depending what trans you have. Let me know, I can email them to you...or maybe find them on Sribd. Merc manuals are numbered.

TRS are strong...but parts are scarce.

X-dimension is very low on them, due to the prop tech at the time. 3 blade Mirage + work really well with TRS, and have a bit of slip when compared to a 4 blade.

TRS upper is very strong, rarely has issues if lubed properly. Lower gear sets are the weak link. Left rotarion prop shaft thrusts gear forward into the case...making it stronger from lower deflection. Right rotation thrusts against the prop shaft inner threaded bearing carrier. Use B1 shims vs the crush washer for gear mesh. Just like setting a rear veh diff...the crush washers are more likely to deform vs solid shims.

You need a special alignment tool when you put the drive on. It has an extra threaded piece that feed into the trans...and also has a disc the goes on the alignment shaft, centering the gimbal.

Google Merctrans...there is typically a few on ebay you can see photos...then you can compare. If you have a look at your trans...and can hardly see anything...then likely a Merctrans. They are shoehorned in tight.

I can’t post pictures yet, I need a few more posts. I looked at the trans this morning. They each have a T-handle cap with a dipstick on the top port side of the case. Both are filled with ATF.

Does that help identify which they are?

Have a look at these photos. Keep in mind the round output end gets placed into the transom plate, and acts as the gimbal bearing, supporting the trans end of the trs input shaft universal joints.

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1st photo is Velvet Drive.
2nd photo is Merctrans.

With the T-handle dipstick description...you likely have a Velvet drive.
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Stronger trans if it's the 72c version vs the 71 series.

Parts should be very easy to source. Gaskets seals bearings etc.

Yup it’s definitely the velvet drive. Thank you very much sir! Id be happy to take a copy of a service manual if you have one.

My next order of business is figuring out why the Stbd engine won’t crank. It turns over fine if I do the ol’ screwdriver bridge trick on the solenoid. The key won’t turn it over though.

The port engine cranked over for about 2 revolutions, then started the solenoid clicking indicitive of a low battery. It’s got 2 brand new batteries.

I’m really considering pulling out every last inch of wiring and starting from absolute zero.

Of course confirm the batts are properly charged and up to the task.

First thing...check the ground connections...and batt terminals.

Ground: Basic obvious good clean metal and use sandpaper to expose fresh copper on the connector.

Batt: Depending on the connector style, wing nut post lead post. Use the ib/outside batt terminal wire brush cleaner.

I like to use bit of grease to arrest any potential oxidation. Works amazingly well...even for the batt terminals.

Service manual. Roger that. Send me your email, and I'll send you the manual for the Velvet Drive TRS...the TRS drive and confirm what engine you have...I'll see if I can find that as well.

I don't have access to them on my phone...so it will be a couple days 'till I get back home.

Art

I need to spam the forum with 3 more posts, then I’ll earn DM and photo posting privileges privileges.

My engines are mercruiser 454s. They are custom built, but they have factory-looking Rochester carbs on top.

Check...nice to have info on the accessories as well. Starter, alt, power steering pump etc. What year is the drive/engine if you know?
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​​Just use this thread to post 3x...to get your 10 posts.

As far as I know, everything is 1986.

I spent the day yesterday gutting wires out of the dash and taking the helm apart. I tried to cut as few wires as I could. It looks like it was mostly factory original wiring, but there were some hack-job quick fixes in there as well. There must be a quarter mile of wire just in the helm.

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The exterior is in better shape than I thought. The top white area needs a heavy cut and polish/wax to shine again. The rest of the boat really just needs a wash & wax.
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TRS drives. Looks like they spin in opposite directions. Do the motors spin in opposite directions too? Or do the transmissions take care of that?
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Twin 454s. They have crane gold rocker arms. I don’t know too much else about them. I’ve heard them run, but it was over a year ago. They have big cams. They both freely crank & turn over.
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Is this a Rochester carb? Should I replace the filter in the front case? How do I refill the bowls since they’ve been sitting?
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Transmission and starter. Kinda hard to work on with the engine hatch in place. I might pull off the engine hatch for a couple months.
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Side view of starter and transmission.
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Other side of transmission. Is this a velvet drive 71C or 72C? Can you tell from looking at the outside?

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Helm. Only the tachs function. I pulled all this stuff out yesterday. It’ll get replaced with autometer marine stuff.
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Steering and throttle linkages are in good shape. How do I clean up the finish on the throttle box? It’s got lumpy, sharp corrosion spots all over it. I wanted to replace it, but wife wants to keep the vintage look.
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Cabin. Needs all new upholstery & a good cleaning.
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Cockpit. We’ll put in new front seats & reupholster the rest.

Great looking Scarab. Really impressive.

TRS props are turning out right now.

Props turning out have stern lifting characteristics. Props turning in will pull the stern into the water...lifting the bow. Diff props and setup will tune your hull to what if needs.
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TRS have left and right prop shafts. They are diff and will have the stamp on the end of the prop threads.

The left turn prop shaft has the gear facing the opposite way.
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​There is no transmission in the TRS drives. Both the Velvet drive and engines both turn the stock direction...they are the same.

TRS drives are very strong...but don't like the hookup up 4 blade props on re-entry into the water. They will serve you well...take care of them, parts are harder to find.

The green id tag on the trans will tell you what it is.

Carb is a quadrajet. You should have a proper spin on filter before carbs. The carb filter is more screen like...last ditch effort to prevent stuff getting in.

You must have mechanical fuel pumps then? Perfect example of why electric fuel pumps are better in a marine application. You pretty much have to crank the engines to activate the mech pumps to fill the bowls.

Alternatively, if you wanted to check the spark plugs...and un-power your ign coil... you can spin the engine faster and maybe get some compression tests on some cylinders. Provided you have plug access...

Basic tune-up...new correctly gapped plugs.

Teleflex throttles do that when in the weather, and age.

It's likely the alum oxidizing under the chrome finish. Probably not a lot you can do.

I have the same controls. I prefer individual levers for transmissions....with separate throttles. Safer, and easier to run I think. To run just the throttle you need to pull the lever to the side. Your hull is pretty modern...no retro look required....lol

Looks like raw water cooling?

Where are you going to run the boat? Salt of Fresh water?

Gelcoat revitalization...depending on how oxidized it is...you can get away with a good 1000 grit buffing compound.

Aqua Buff 1000 is maybe the best? It's water based not petrol based. Get the smaller 500ml size. Lots if good youtube vids on how to use it.

Agua Buff 1000...then Aqua Buff 2000...
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If you need to wet sand...1000 grit...then aqua buff 1000/2000.
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Then use a good wax to bring it up.

PRO brand Aircraft RV boat wax is really good.

Do a test patch of the process in a small area to confirm the outcome.
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If you end up wet sanding...you may end up with a better gelcoat surface than factory.

division1 one here...spent 80hrs sanding and filling his engine bay to perfection...before painting.
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What cost would that add to the factory price? Even finding motivated employees to dig in deep on a task like that is difficult at best.

​​​​If the deck it really oxidized...I've found the dollar store green scrubby rectangles are great for removing the bulk of the powdery residue...use with water of course.

The Green tag Transmissions are C72s Red tags are C71.

Congrats! Your boat has lots of potential. The cabin looks to be in great shape, and hopefully, your motors and drives are in excellent running condition too. These mid-'80s offshore performance boats, in the right colors, are now cool classics. Your guys' boat is i.m.h.o. in one of the best '80s color combinations. We've got a local Scarab III 340, in similar colors with twin 450 hp 502s and TRS drives, here in Newport Beach, SoCal, and it always gets thumbs way up. Your teak looks to be in good condition and I would certainly keep that classy look. The dash would be nice if you upgraded it, but I'd keep it black and definitely not put some carbon-looking, not period-correct stuff on this classic. Keep it ol' school and maybe even do the cockpit interior in a high-quality tuck-and-roll vinyl that maybe goes in matching white, red, silver, and black? Good luck with a very nice project.

Great info on the color coding.

Very nice Scarab III. I like how they setup the arch with the paint and location. Makes it feel part of the styling rather than an add on.
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+1 on the no Carbon Fibre.

A nice aluminum cut to size is pretty easy for a project. You could even get it anodized.

With the online software free...and the online inexpensive R&D places....you could map it out and they would build it and send it. Often for cheaper than buying the metals to fab it yourself. Obviously, a 1/8" small sheet of alum is pretty cheap to source, but shaped and welded pieces, there is merit.

Even to have stuff cut and sized, but sent unwelded. Often really economical. The CNC automation at smaller scale has really changed the industry.

I’ve been in Europe for a while so the project sat for a month. I got to dig into it today.

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I gutted the boat’s wiring today. The amount of hot, loose, random wires in the helm and engine bay was alarming. I decided to start over from zero & cut everything out.
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All the helm stuff was relatively easy to unplug, cut, and remove. I’m not gonna reuse any of it.
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Once I pulled all the harnesses out of the gun whale & got them to the engine bay, they were relatively easy to identify between: Fuel sender Hatch opening ram L/R drive trim pumps L/R k plane Stereo (looked like a 15 year old installed the stereo) The actual engine harnesses are still a mystery. It’ll take a couple days to sort that out.

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I also finished “rebuilding” my compass today. These things are like $300 new, which is asinine. I used a headlight restorer kit to cut & buff the acrylic. It was so yellowed & hazed you couldn’t see thru it initially. It took about 90 minutes.
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I sealed the acrylic to the plastic body using automotive RTV. It was leaking from the seam. I drained the nasty old oil, and refilled it with 3 little bottles of J&J baby oil. I had to use a med syringe to fill it. Total spent on the job was $12.

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After gutting a half mile of useless & broken wires out of the boat, started rigging up new wiring. I moved the battery switches out of the engine bay and put them under the seat. I built new 0AWG cables and laced them more conveniently than they were before. I put shrink wrap on all the ends.
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I started wiring up a more modern “blue sea systems” fuse box under the helm. I ran 4AWG cable from the battery switch to the fuse box. The boat previously had glass barrel fuses.

Awesome project. Keep the updates coming!

On the J&J mineral oil.......im not 100% sure of this but depending on its viscosity it may slow the reaction time of the compass....probably not a big deal in most cases but something to keep in mind.....also i know that Ritchie uses an product called Isopar L Its some sort of refined synthetic fluid. Most people use an odorless mineral spirits for them. DO NOT USE GLYCERINE! I found out the hard way.....that the stuff may not freeze solid, but it will not come back clear after it starts to solidify! Found that out the hard way :(

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I dropped this screw/bolt/pin that connects the drive tiller arm to the steering Ram. It went into the transom assembly and it’s resting in there, bottom center. I saw it with a borescope. It doesn’t appear to be touching the driveshaft or any moving parts.

1. Can I leave it there? Is it gonna destroy things? Ive tried to fish it out for the last 2 days. I can get it with ANY tools, magnets, etc. I found the castle nut that goes to it while searching.

2. Can I buy a replacement? Anyone got a part # or link to a shop that sells them?

Long time without posting. I’ve got 95% of the wiring done. I used a couple ABS plastic sheets for the helm, and a set of SIERRA AMEGA gauges. The autometer set was way out of my budget. The switch panel is an MKING Chinese junk panel from Amazon.

I ought to be able to start the engines within a month, and sea trial in May.

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Here is the “nearly” finished helm. I still have a small bit of wiring left to do. The fuel gauge isn’t centered & looks kinda dumb, but oh well. I’m building this thing for family fun, not to win at boat shows.
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Same helm, partially assembled.
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Back of the gauge clusters as I was assembling them.

I don't see the fuel guage as out of place. When viewed as a whole dash, the fuel ga lines up well.

Nice wiring work. I just saw a guy last eve with the Tide Nascar youtube site...I guess he bought it...but the wiring work was atrocious and all over the place.

Once on the water and functional, you can tweak as you go.

The wife mostly judges poorly when the boat never leaves the yard....lol.

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New, functional winch installed on the trailer.
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Gauges all in and op-checked. GPS speedo finally works. I tried to build my own gps antenna, but ended up needing one from the company that built the gauges. Bluetooth stereo in the bottom center sounds great.