Bertram 20 inboard to outboard

Berty20

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Feb 8, 2010
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7
Hi I am new to this site but it seems to have a heap of info
I am currently doing up a Bertram 20
I am looking for any info on converting from inboard to outboard
thinking of poding the boat. any ones point of veiw would be great
is it a possibilty or am I wasting my time
thanks Scott
 

Bondo

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Apr 17, 2002
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71,157
Re: Bertram 20 inboard to outboard

Ayuh,.... Welcome Aboard Scott,...

It might work, but I've seen several hulls that were I/Os converted to outboards, that didn't work worth a danm....
Is this a full Inboard,..??
Usually the bottom of the hull is So different, that an Outboard won't work...
 

tashasdaddy

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Nov 11, 2005
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51,019
Re: Bertram 20 inboard to outboard

most are not please with the outcome.
 

erikgreen

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Jan 8, 2007
Messages
3,105
Re: Bertram 20 inboard to outboard

Like most of the other mods you make to boats, it's possible, the question is whether it's a good idea or not.

If you're ok with paying the cash and doing the work, then you can do it and you'll end up with a boat that floats and will move across the water. It may not handle as well as a boat designed for outboards (or at all) or it may give an uncomfortable ride, or be hard to steer, but it's not going to explode or anything if you stick outboards on it.

If you decide to go forward with this, I'd start by asking the manufacturer if that model of boat can work with outboard drive. They may even have made an identical model with outboards so you know it will work.

If you can't talk to them (I don't remember if they're still around or not) or they don't have an outboard version of the boat, then you can proceed by drawing up plans to replace/reinforce the transom (for inboards it's relatively weak, for an outboard it needs to be much stronger) and figuring out how you'll mount the outboards on it, where the fuel lines will go, etc.

Then plan on adjusting trim once you get it assembled and into the water.. moving the engine weight back will tend to push your bow up, so you'll want to move some weight forward to adjust for that.

That's the longish answer to your question.. if you're asking if this is a common thing that people have done successfully, the answer is that it's not common because it's expensive to do and doesn't usually come out too well, but people have done it and been happy with the result too.

Erik
 

salty87

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Aug 12, 2003
Messages
2,327
Re: Bertram 20 inboard to outboard

why don't you want to stay inboard?

if it's a choice between fixing the engine or re-building the transom, i'd stick with the inboard. once the engine is running good, you're done and back in business. if you go the o/b route, there's a chance you might not be happy with the results. seems kind of a shame to turn an old bertram into a franken-outboard. a fair amount of work too. i'd rather turn a wrench than grind fiberglass.
 

Berty20

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Joined
Feb 8, 2010
Messages
7
Re: Bertram 20 inboard to outboard

Hi all thank you all for your info
salty87 it does not have a motor at all it had a Volvo penta petrol
the only reason I am thinking of outboard is a lot of people are telling me a
petrol in board is a bomb waiting to go off.
If I was to stay with the inboard
what motor would be best it has a Volvo penta leg.
Thanks scott
 

Berty20

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Joined
Feb 8, 2010
Messages
7
Re: Bertram 20 inboard to outboard

Bond-0 it is a stern drive.
Thanks Scott
 

tashasdaddy

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Nov 11, 2005
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51,019
Re: Bertram 20 inboard to outboard

well we need to know more about the boat, there have been many marinize engines, coupled to Volvo legs. GM, Ford etc. need more info.
 

salty87

Commander
Joined
Aug 12, 2003
Messages
2,327
Re: Bertram 20 inboard to outboard

ahh....you're talking about an i/o. i'm not much help there, i thought you had true inboard.

from everything i've read about a volvo, they're solid.

as far as a gas inboard (or i/o) being a time bomb, i wouldn't listen to those people too much. there are many thousands of boats out there that seem to manage just fine.
 

Berty20

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Joined
Feb 8, 2010
Messages
7
Re: Bertram 20 inboard to outboard

Hi tashassdady
the boat is a 20ft Bertram Bahai mar it had a Volvo penta
petrol in it but I bought it with no motor as it was seized
it has a Volvo leg a 270 I think but I will check.
Is there any other info I can give that would help.
Thanks Scott
 

erikgreen

Captain
Joined
Jan 8, 2007
Messages
3,105
Re: Bertram 20 inboard to outboard

270 is a fairly modern volvo drive I believe... post in the I/O and engine forum and someone will tell you all about it, plus I believe manuals for it are stickied to the top of the forum.

Probably it's going to be a volvo or GM engine that attaches to your existing motor mounts and transom. A new or reman engine like that will cost less than almost any larger outboard, will have more power, and will require less work to get going.

Volvo penta make excellent outdrive systems... best out there, basically. Service the drive and transom, replace the engine, and you're probably good to go for 10-15 years if you keep maintenance up.

Erik
 
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