Building twin outboards for my Convincor

[DropTop5.0]

I bought the ’85 Convincor without power for a few different reasons: 1) I didn’t have the extra cash laying around 2) I wasn’t sure exactly what power to put on it 3) wasn’t sure if I wanted to go with 20” or 25” motors etc…

In the evenings I’m always surfing craigslist and other sites for entertainment. I’ve always been this way; for some reason I get a kick out of reading peoples for sale ads and thinking this or that would be cool to have. In my searching for “Mercury 200” I came across an add for “1981 24 Superboat with custom swim platform” and here’s a pic of the boat.


The boat had a Mercury 200 hanging off the back with side mounted hydraulic steering so it peaked my interest. As it turns out, this boat had twin 200s at one time with 20” mids, low water pickups, and full Latham steering which is exactly what I was looking for. Long story short the guy had a couple of kids and the boat wasn’t all that friendly with twins so he put a bracket on the back and ran a single on there. For some reason he disassembled one motor (removed the powerhead, mid, clamp, and lower). The complete motor has low compression and will need a rebuild. For $1,500 I got a whole pile of mid 80’s mercury stuff and I’m not positive if it’s junk or if I have some good stuff here. I figure worst case scenario the Latham steering is worth my investment.

For background information, I’m not oblivious to working on my cars and bikes but I really haven’t been doing this for the last six or seven years. I’m relatively new to boating and I have never worked on an outboard. I still have a lot to learn when it comes to working on motors and understanding what a proper and safe setup is so I’ll be all ears (or eyes) for those who would like to help me through this. Jupiter Pulsare, SCT, Demag67 and many other have been extremely helpful with advice and knowledge. Thank you very much gentlemen.

So here I am with a pile parts, I just bought a cherry picker and some lumber to build an engine stand. I was planning on building this one I found on iboats http://forums.iboats.com/forum/engi...327-building-an-o-b-motor-stand-instructional.

Here are a few pics for your viewing pleasure:

 

[corey331]

Looks like we both have big winter projects in front of us!!! I like it!! i cant wait ti see this thing in person and running!!

 

[DropTop5.0]

I was thinking the same thing! Same as you, I like to be a little different and there aren't too many outboard Convincors out there. I'm on a little bit of a budget but so I'll need to spend my dollars wisely.

For the Turbo Buick lovers out there my brother's Firechicken is making 900+ out of a little V6. They are some cool motors.

 

[mragu]

drop, did you get the boat too for $1500.00? If so, would you be interested in selling the platform/bracket. If you are interested in selling it, I would like to know setback distance, overall width and degree of angle. Also, how much would you want for it. Thanks, Mike

 

[Instigator]

Very cool.
I too am a fan of the O/B Convincors.
I've owned and restored two 24' twin O/B s
Sonics only because I couldn't find a Convincor at the time.

Ton of work but big fun when complete and an absolute blast to drive fast.
Good luck w/your restoration.

 

[corey331]

I think it should now be a requirement that one MUST post pictures and or talk about a turbo buick or turbo buick powered vehicle in all build threads...

 

[RNGRDVE]

How about we pull the power from your GNX and drop it in my Starfire hull.

 

[Gimme Fuel]

How about we pull the power from your GNX and drop it in my Starfire hull.

That would be wicked......

 

[mishawakajim]

Your brothers 68 looks sharp and 900+ HP is pretty impressive out of a V6. Good luck on your winter build. Looking forward to future posts to the thread. Jim

 

[DropTop5.0]

drop, did you get the boat too for $1500.00? If so, would you be interested in selling the platform/bracket. If you are interested in selling it, I would like to know setback distance, overall width and degree of angle. Also, how much would you want for it. Thanks, Mike

I did not buy the boat or trailer. It's still listed on the Norfolk, VA Craigslist add. You can give him a call.

Very cool.
I too am a fan of the O/B Convincors.
I've owned and restored two 24' twin O/B s
Sonics only because I couldn't find a Convincor at the time.

Ton of work but big fun when complete and an absolute blast to drive fast.
Good luck w/your restoration.

I've read your build threads often and have really enjoyed the craftsmanship you put into your builds. If I had the funds, I would have purchased that Sonic from you but I just couldn't find a way to make it work. I don't like loans; I'm more of a cash person for my toys.

 

[seef158]

MN convincor?

Drop top,
Did you buy the two tone blue checkmate out of minnesota here?

 

[DropTop5.0]

Yep, long drive too.

 

[demag67]

Wonder if he will sell that helm pump

 

[DropTop5.0]

Hey Bruce - I bought the whole steering package including helm. I plan to use it though. If I looked up the right thing, the helm is $900+ new.

 

[Instigator]

I don't like loans; I'm more of a cash person for my toys.

Agreed.

I can't deal with letting it set while I make payments. A project that's paid for on the other hand, can sit (for free) while collecting pieces, funds and motivation.

I remember that Convincor. Very sharp.

Thanks for the compliments on the Sonics and other projects.
I learned what I know by having champagne taste on a beer budget.

I restored the 2nd Sonic down in the Fla. heat and it was quite the challenge.
Part way through and at a point where I felt like all I was doing was grinding glass and seeing no progress, my wife says: "screw it, lets go to the Miami show and buy a new one and start boating."
I knew how it would end but thought it would be a fun day/break so we went.
We did that for two different yrs.
I found a single boat both times that I would trade my dream, completed
Sonic for.
One was the then new 30' O/B Concept O/B and the other was the 34' Velocity O/B. I knew both would be well north of $100K to get the way I wanted and neither would do all that the Sonic would.

The fun part is ending up w/exactly what you want and if done proper like, well nicer than ever came from the factory.
I remember having a 2 page list of improvements I wanted to do to my first Sonic but never did.
I did every one of those improvements to the 2nd one and sold it when I couldn't think of anything else.

Take your time and you should end up w/something very special.
My first Sonic came w/twin 2.4 Mercs that I contemplated rebuilding and keeping.
Think of them like your 5.0 Fords. They've been built for ever which equals tons of cheap parts and almost as importantly, tons of good info on hopping them up.
I would caution you on what you do though. W/that boat you need torque not HP's.
If you use someones port map from the motor off their 500 lb potato chip
you will end up w/a turd. High ports rob torque, period.
Think of taking a wild cam w/a ton of over lap out of a 3K lb fox body w/gears and a loose convertor and put it in an otherwise stock, 4500 lb Crown Vic.
Exactly the same.
Compression also equals high octane/$$$ which sounds fine when building but not at the pumps. I remember the clerk at the local station freaking out when I had them reset the $100. limit on my pump for the 3rd time.
I did the same thing, the week before, same station, same clerk
That was w/crap gas too.

Good luck and let me know if you ever need any help.

I am jealous of what you will end up with.

 

[JUPITER PULSARE]

Looking forward to watching this re-rig. There are not alot of twin outboard Checkmates running around! Stock twin 2.4L 200's will send that boat well north of 70mph GPS and not require alot of $$$ to put together. Focus on rigging the boat cleanly with nice controls, steering, wingplates, harness's, etc. Keep the powerheads stock and trouble free and you'll have a great boat to be proud of!!!

 

[atc250r]

Agreed. The devil is in the details. Rigging tubes, clamping the hydraulic steering hoses, and stuff like that take a nice boat to the next level and do it for not a lot of money.

John

 

[DropTop5.0]

Thanks for all the comments so far. I totally agree about the "Devil is in the Details. I'm still building my first engine stand four days later. Boy am I out of practice. I cut all my pieces using the miter when I should have used the bevel part of the saw. At least I had a good laugh at myself.

I'm not sure if these motors are stock or not. They came off a Superboat and they have an "Island Perfromance Marine" sticker on the airbox. Does anyone know of this company in Lindenhurst, NY? I believe the owners name is Mario. I gave him a call and asked how much for a rebuild on the one that's down on compression and he quoted around $2,200ish but said it all depends on whats going on inside there.

 

[atc250r]

If you're going to have them rebuilt I'd either ship them down to Chris Carson in FL or bring them to Fuller Marine in NJ.

 

[JUPITER PULSARE]

If you're going to have them rebuilt I'd either ship them down to Chris Carson in FL or bring them to Fuller Marine in NJ.

Or Diamond Marine:

http://www.google.com/url?sa=t&rct=...=jMstXZeNCeiR0J2mRVRC4g&bvm=bv.77161500,d.eXY