Seeking advice on a B20 Repower

[Sean B]

I picked up a 1966 B20 Moppie a little while ago, with the original straight six engine (recently rebuilt and still running good), and have been thinking about a repower. Mainly because the original 1966 Mercruiser outdrive doesn't have true trim... you can only run it up, after which you manually put this metal hook thing on the transom to hang the outdrive in the "up" position. I've never seen or heard of such a contraption before this boat, and I don't much like it.

Anyway, I hadn't given outboard engines much thought, but after looking at John F.'s B20 photos... I am now. How big of a deal is it to cut and reinforce the transom on a B20? This would go beyond my skills but I know a local fiberglass guy who could do it. Any particular reason to use (or not use) a transom bracket on a 20 Moppie?

Previous to this I had been thinking about a V6 with a new outdrive. Big money though.

Here are some photos of the new (old) money hole
























It even came with an original Bertram trailer. I think this thing weighs as much as the boat

[Yannis]

Sean,
I don't know what you'll eventually do with the engine, however this is a truly beautiful boat, in such a good condition...
If it were me I'd keep an I/O as it's what the original boat was designed for, but as you're saying, its expensive.
Good luck and happy cruising with whatever you choose.

[John F.]

Sean-

She's very nice and very clean. I don't know what was involved in converting mine. When I bought mine, I went by the fiberglass shop that had done the work. As I remember, they told me that it'd cost about $5k if I brought them another B20 and had the outboard conversion done. That was 5 or so years ago. Their work was good enough, but certainly not flawless. It doesn't look to me like they did anything regarding beefing up the stringers or tying the transom into them. It looks like they beefed up the transom a lot. Unfortunately, they used wood. I'm pretty sure the transom is wet in spots, and I know the stringers and deck need to be redone.

I friend of mine started a B20 project and was having his done with a bracket. Most I've seen had had brackets. I personally don't like the look, but the B20s I've seen that have been converted have all been brackets. I've never been on one with a bracket, so I can't tell you how they ride. I can tell you that my B20 rides great, and I really like O/Bs. When this one goes--it just keeps running--I want to have the stringers/deck/paint done, and hang a 250 on her.

That said, your B20 is so clean and looks so right the way it is, I'd just run her as is and worry about the repower when something really expensive breaks. You have a lift, and that should help.

If you (or anybody else) ever makes it to the Annapolis, stop by and we'll go for ride. I'll put the B20 ride up against any boat its size.

John

[Sean B]

That's not my lift, unfortunately, that's a photo from when I went to look at the boat.

I'll be launching it from the trailer, which is the main reason I need the outdrive trim to work properly. The reason that I'm thinking repower is that both hydraulic hoses that operate the tilt are blown, something that I should have caught before buying it, but didn't, so it's my problem now.







Apparently replacing those hoses on that old I/O unit involves pulling the whole thing apart and tons of labor costs. The local mechanic I like is familiar with these old I/O's, and says he doesn't really want to do it because he's parts likely won't be available for whatever he finds to be needed after it's apart, and he's afraid he won't be able to get it back together in working order. I appreciate the honesty. Also he said that the labor $$ would be better spent installing a new unit. This makes a lot of sense to me, especially considering the tilt-only capability with that steel rod contraption holding the unit up doesn't exactly fill me with joy.

I have the outboard conversion idea in the back of my mind, and I have had and like large outboards too, but it seems like that would actually cost quite a bit more. I do like the looks and lines of the boat as she is with an I/O.

So - I'm thinking I will install a new V6 EFI engine and a new modern outdrive along with it. Any advice on what I should be shopping for in a new engine and outdrive would be much appreciated.

[John F.]

Sean

Ask Ian about his B20 Bahia. He just redid it, and repowered with an I/O.

John

[ianupton]

Sean -

I put a V6 volvo and duoprop in mine.

I don't have the correct props now, but that package will push her to about 50 mph.

I had thought about outboard and might do it some time on a different boat. I would do it like John's with engine well and not do a bracket. I think the bracket on this hull makes it look like an outboard is chasing the boat.

I think the outboard might be quieter. Mine has some whine at certain RPMs and not sure if when I add sound deadening it will reduce or not.

My mom mentioned just today that when I took off from the dock she thought something wasn't right. I need to check it out.

I think when it is all done, IO or outboard if you are buying g new would be about the same. A lot more labor to install an IO. Glass work tradeoff is probably the same.

Ian.

[John F.]

Sean

I had a little formula with an io years ago. I think it had the same problem. The replacement hoses were routed directly from the hydraulic pump through the transom to fittings on the cylinders. They bypassed the out drive. Just a thought

John

[Sean B]

That seems painfully obvious now that you say it, but I hadn't thought of that solution myself. Thanks! I might just do that and play with it for a while before I go for the big repower expense. I was thinking about how to rig up something temporarily just to use it for a while as is. For us in Florida the prime boating season begins now when it finally cools down, so having the 20 suddenly broke was a bummer. Thanks

[JohnD]

Sean,

Another option would be to replace the old pre-alpha with and Alpha 1 r 2 and keep the straight 6, that's what I did, but now the motor is bad.

Br,
John

[Rocket]

There is nothing so nice as new power. It just works, it starts every time, they are easy to maintain, the fuel injected motors are easy on fuel. The I/O would be the most simple swap for sure. That boat looks mint, do you know if there is any wet foam? Do you know if the fuel tank is okay?

I think Ian has a great package on his Bahia Mar, I have the 5.7 Volvo driving a DuoProp and the performance and economy are truly spectacular. The nice thing about the DuopProp is that the boat steers really well both in forward and reverse, doesn't lay over because of the torque and is really easy on fuel.

I am not an outboard hater, they really have a role to play particularly in this size boat, but so much change is required to make it happen that unless there is a compelling reason to switch to an outboard, I would be looking at I/O solutions that fit within your budget framework.

[Sean B]

The gas tank has been replaced already with a poly tank. I was told that the foam was removed during a previous rebuild, but I've learned a few things that makes me doubt the seller's word now. So basically I don't know about the foam. Is there a way to tell, short of cutting holes in the deck? There is a slightly soft spot on the deck near the port chair.

So is the "Alpha 1 r2" a bolt-in replacement for this "pre-Alpha?" Where do you find one? I don't know much at all about I/O's, in fact this is my first one. If I do decide to pull the straight six, do you want it? It was recently rebuilt and it runs like a champ.

It is a very clean boat for it's age but she has some issues.

[Sean B]

Sean,

Another option would be to replace the old pre-alpha with and Alpha 1 r 2 and keep the straight 6, that's what I did, but now the motor is bad.

Br,
John

http://r.ebay.com/tB8Ohc

Is this the drive that you mean? It still seems to still need the trim/tilt cylinders

[Rocket]

The easiest way to check for wet foam is to weigh the boat. If there is a commercial truck scale nearby weigh your truck and trailer first, then pull the boat out and weigh it again with the boat on. We can then compare it to the factory weight and establish if you are too heavy or not.

Pete Fallon may have another way that is better. I'm my Baron the foam near the bilge was totally soaked and it weighed 1,500 lbs more than it should have.

[JohnD]

Sean,

I have a mechanic who did mine out of salvage parts (I'm doing this on the cheap). He handled getting and install the parts needed, reusing the existing trim controls. Size wise the new either fit or was slightly large, so just a little cutting was needed, no need for filling in any areas.

My motor is dead and I'm debating on whether to re-build or just try and find and RTO v6; the $400-500 for the straight 6 exhaust manifold is tough to swallow and they're getting hard to find. I do like the simplicity of them. One of these day's I'm going to stop at CrazyRays (local junk yard) and see if I can find an old Chevy 250 to use for short $$.



br,
John

[Sean B]

The easiest way to check for wet foam is to weigh the boat. If there is a commercial truck scale nearby weigh your truck and trailer first, then pull the boat out and weigh it again with the boat on. We can then compare it to the factory weight and establish if you are too heavy or not.

Pete Fallon may have another way that is better. I'm my Baron the foam near the bilge was totally soaked and it weighed 1,500 lbs more than it should have.

I will try to figure out where to find a truck scale locally.

I pulled the removable hatch from above/around the fuel tank. Through the very small gaps I can see that there is some foam back in there. Bummer. Looks like the seller told me a fib when he said he had all the bilge foam removed.

For those who have done it in a B20, can the fuel tank be pulled and the foam removed from that area? Or does the entire deck need to be cut out to do the job?

[ianupton]

Fuel tank cam come out without removing deck. If original, there is a removable section held down with screws.

Should not be any foam around tank.

Ian.

[ianupton]

Sean - I just re read your post.

The foam that you see is it the foam from outboard of the stringers?

Ian.

[Sean B]

It's hard to say. What I can see is through the very small gaps between the (not original) poly tank and the deck. I didn't explain my question very well. What I meant to ask was, can I remove any foam that's left in there through that hatch if I pull the fuel tank out.

I do have an endoscope inspection camera, I should poke around with that and try to see what's in there.

[ianupton]

If you took the removable section of floor out. You should have full access to the space that the original tank occupied.

This is the picture of my Bahia with the floor section removed and the old tank out.



If they did a rebuild and changed configuration I am not sure.

Ian.

[Sean B]

so Bertram glassed around all four sides of the fuel tank area? If that's the case then shit, I can't get into the blige through that opening to access wet foam or anything else. I'm wondering if they installed those sides on my boat, it looks like not, but I probably need to pull the fuel tank to find out (it's very tightly fitted in there). What year is your B20?

Thanks for all the help !

[ianupton]

Sean - what does your look like?

Mine is a 66.

Could they have foamed the tank in place and that is what you are seeing? The Bertram foam if dry is a nice white. The two part that we put under my new floor is yellowish.

Ian.