Please Help Again.. the up's and DOWN'S of Resto

[Cast-A-Way]

Well I made another bobo I think (first time restoration)

I have an 18 foot bayliner avanti I/O With a 4.3 omc and cobra outdrive
that needed a new transom stringers and deck !

I have completed all the work and tonight I cut the I/O hole to mount the outdive and noticed that my transom is now 3" thick....
I do not have the engine mounted yet

I lost my little peice of paper that I had the original measurement on but I think the transom was 2" 1/2 or 2" 3/4.
How thick should it be ?

Any solutions asside from grinding away what I did ?
What kind of effect can this have on the motor "shaft" if I get longer bolts for the outdrive ??

Thank you in advance

 

[Mark42]

Re: Please Help Again.. the up's and DOWN'S of Resto

You might get a better response in the i/o forums. I don't know much about outdrive setup, but I can tell you if you do end up having to remove material from the transom, use a router, don't grind it. The router will make a nice clean recess.

 

[Cast-A-Way]

Re: Please Help Again.. the up's and DOWN'S of Resto

You might get a better response in the i/o forums. I don't know much about outdrive setup, but I can tell you if you do end up having to remove material from the transom, use a router, don't grind it. The router will make a nice clean recess.

Very nice Idea
I guess I could recess a tad and it should be ok !!

 

[Bondo]

Re: Please Help Again.. the up's and DOWN'S of Resto

Ayuh,.... I don't do OMCs,...

But,...
Mercruisers Require 2".... No more than 2, 1/8"....

 

[Cast-A-Way]

Re: Please Help Again.. the up's and DOWN'S of Resto

Would I lose any structural strength if I routered out 3/4" then reglass ?

 

[tashasdaddy]

Re: Please Help Again.. the up's and DOWN'S of Resto

not much. but i think you need to take out more than that. because you have to seal it.

 

[Don S]

Re: Please Help Again.. the up's and DOWN'S of Resto

From the installation manual

Transom Dimension Limits

Before beginning the installation, it is the installer?s responsibility
to determine that the boat transom meets
the following requirements:

? Maximum transom thickness: 2-1/4 in. (57 mm)
? Minimum transom thickness: 1-3/4 in. (44 mm)
? Inside transom area must be flat within 1/8 in. (3.17 mm)
? Outside transom area must be flat within 1/16 in. (1.57 mm)
? Inside and outside transom area must be parallel within ? 1/8 in. (3.17 mm)

 

[Cast-A-Way]

Re: Please Help Again.. the up's and DOWN'S of Resto

not much. but i think you need to take out more than that. because you have to seal it.

Should I make my final thickness about 2" 1/4 ??

 

[Cast-A-Way]

Re: Please Help Again.. the up's and DOWN'S of Resto

From the installation manual

Transom Dimension Limits

Before beginning the installation, it is the installer?s responsibility
to determine that the boat transom meets
the following requirements:

? Maximum transom thickness: 2-1/4 in. (57 mm)
? Minimum transom thickness: 1-3/4 in. (44 mm)
? Inside transom area must be flat within 1/8 in. (3.17 mm)
? Outside transom area must be flat within 1/16 in. (1.57 mm)
? Inside and outside transom area must be parallel within ? 1/8 in. (3.17 mm)

That's Perfect

I know what I am doing tonight !!!
Sometimes it feels like 2 steps forward and 1 step back

I should post pic's also ( I am bad for that )

 

[daydreamer1252]

Re: Please Help Again.. the up's and DOWN'S of Resto

DonS,

Don't want to Hijack someone else's thread....Are the hull transom specifications you listed above the same for a Mercruiser ('84 120hp)? If not can you post a link to the equivalent numbers for Mercruiser?

Thanks.

 

[Cast-A-Way]

Re: Please Help Again.. the up's and DOWN'S of Resto

I agree daydreamer 1252 it is very useful info

 

[oops!]

Re: Please Help Again.. the up's and DOWN'S of Resto

don will have that info, but it is very close.....

the transom on my ray is 3 ins right now and after the gellcoat goes on it will be even thicker.....so im going to be doing the same operation as you....

pay special attention to the other dimentions don gave you, in particular....it inside out side paralell mesirements.....an eighth isnt very much.....
make sure you take into account the layers of new glass you are adding...

a jig and a router would make short work of that particular operation...

a grinder would be wavy at the edges where you need the seal......

what tool are you planning on using?

 

[Cast-A-Way]

Re: Please Help Again.. the up's and DOWN'S of Resto

I got it done last night and used a grinder on the inside of the transom to recess the outdrive mount after tracing it, and it seems to be pretty good
I will end up with about 2 1/2" after adding glass (that's what was there before)

I think this should be ok ??
I will take pictures tonight and show you guy's for your opinion