offshore outboard bracket on an ss180??

bob johnson

Rear Admiral
Joined
Feb 25, 2009
Messages
4,306
ok in idle time here thinking of all my crazy ideas......

I had looked at another memebers 22 ft mariner....loved the room, then saw another thread here were a guy in wisconsin rebuilt an islander into a side console for duck hunting..it looked fantastic...

sooo

while i think the 22 footer i saw was a little too much to bite off right now, I ll keep my 18.5 footer since i have taken all the paint off already...

but liking all the room in the 22 ft er...i am thinking about leaving the splash well out of my ss180, and installed a full height transom, and adding an offshore bracket to hang my motor on....... seems like id gain almost 2 foot of floor space to walk on..inside...id keep water from coming in the back of the boat...and id be able to mount the motor higher...since there would be about 2 feet of set back on an offshore bracket...

I see them cheap in fiberglass, but think since i have plenty of aluminum on hand...I could weld one up.

my unknown is the leveraged draft increase on the stern......about how much would we be talking ..maybe?

i know a lot of you guys have switched motors on your starcrafts....you know how the draft changed when you went from say a 70 hp to a 140 hp.... or if any of you guys added a medium to large set back hydraulic jack plate....you got the same kind of leverage squat.....what was it??

Ill probably hang a 320lb ocean pro 115 on this boat when done..

if this is feasable...It would make life easier than unloading one boat, finding a laonger boat, and starting all over again tearing it down...


hope to hear from some of you

bob
 

64osby

Admiral
Joined
Jul 28, 2009
Messages
6,826
Re: offshore outboard bracket on an ss180??

Can't help you with the draft / bracket question.

To pick up all the space are you looking at, do you have an under floor tank, and where will the vro go, if you have one. Also battery placement, maybe Jason can help with that.

You might be better off reducing the spashwell, I think it's MichealP that did a real nice fit on that.
 

bob johnson

Rear Admiral
Joined
Feb 25, 2009
Messages
4,306
Re: offshore outboard bracket on an ss180??

I am looking at forward fuel tank(s). as well as batteries under my side console. I have a 53 gallon aluminum under the floor tank...but it is too long to fit with the hieght it has....if i cut the length down....it will fit in that stepped forward spot. ( if i go with a single tank under the floor) if portable tanks they will be up forward as well. I pre mix my gas as well... about the only thing in the back will be my extra transom bracing( 1.5" square tubing with flanges at an angle going from the transom to the floor on either side of the beefed up factory brace.. and in between all those somehow will be two large bilge pumps...but they should be under the floor... the braces maybe still be showing 18-24 " off the transom still( about 45 degrees mounted about mid height of a factory transom board)...Ill have a single plate mounted on the inside of the transom that will span to be under both the new braces...I am not sure if it will be SS or aluminum... i have both materials on hand.

looking at some aluminum brackets on ebay...they seem easy enough to make... there is one there now for only $300...but it is way longer than i would like...its got to be 30-36"!!!

bob
 

64osby

Admiral
Joined
Jul 28, 2009
Messages
6,826
Re: offshore outboard bracket on an ss180??

The battery cables will be long, thick and pricey.

Long run for portable tanks, might need a bigger fuel pump at some point if you go that route.

Sounds like a nice project you have going.

We have a 21' Mariner and really love it. Can't wait to get it out this year. Hopefully really soon.
 

bob johnson

Rear Admiral
Joined
Feb 25, 2009
Messages
4,306
Re: offshore outboard bracket on an ss180??

I have a 20.5 ft lowe with a center console that is moved forward from factory...i have the two batteries under the seat in front of the console. i also have 2 9 gallon tanks under the front deck...

been running that for 2 years now....I got an onboard charger....so i havent noticed any electrical issues..

I have replaced the 115 ocean runners fuel pump....but it was leaking behind the pump....it probably was still ok...

I run the tanks lines to a diverter valve and then to a fuel seperator cannister....I bet i got over 21 feet of gas line... I bought #2 battery cable...

if i had issues with that boat, i would propose to duplicate it....the motor bracket would only add 2 ftt maybe to the gas lines and battery cables...thats nothing

I got some 5/16ths plate aluminum....i think would be enough to a box bracket......maybe Ill just mount the motor normal to get a baseline toi compare...then try to implement my idea afterwards.....especially if i am wanting more open space


bob
 

magnumdeke

Chief Petty Officer
Joined
Apr 13, 2010
Messages
626
Re: offshore outboard bracket on an ss180??

Been looking in to this as an option for gaining room in a Islander, for every foot of boat length 1" of motor setback is recommended and for every foot of setback 1" of height above the old engine height is recommended so 18' boat = 18" bracket with motor 1.5 to 2 inches higher than previously mounted. this is just info I have found in my searches take it for what it is!!, also most bracket builders do not recommend a bracket for any thing under 20' due to weight shift creating imbalance front to rear.
 

bob johnson

Rear Admiral
Joined
Feb 25, 2009
Messages
4,306
Re: offshore outboard bracket on an ss180??

Been looking in to this as an option for gaining room in a Islander, for every foot of boat length 1" of motor setback is recommended and for every foot of setback 1" of height above the old engine height is recommended so 18' boat = 18" bracket with motor 1.5 to 2 inches higher than previously mounted. this is just info I have found in my searches take it for what it is!!, also most bracket builders do not recommend a bracket for any thing under 20' due to weight shift creating imbalance front to rear.

would you think the fuel tank in the bow as well as two marine batteries in the first 5 feet of the boat would offset that??

the batteries might only be about 100-120 lbs total...but the gas if 28 gallons could be substantial...since they usually have the fuel tanks in the back near the motor!!!

if i go with a shorter bracket ie leass than 24", i think Id have to make sure i can tilt the motor without it hitting the transom.. On my 20.5 ft low I installed a 10" set back jack plate and I also tried to install a splash sheild over the top of the lower portion of the transom( to keep water out when backing)...but the motor cover would hit it if i tilted the motor for trailering ....

bob
 

magnumdeke

Chief Petty Officer
Joined
Apr 13, 2010
Messages
626
Re: offshore outboard bracket on an ss180??

Well you are not always going to have a full tank, I think 18" would be close to clearing but you need to measure your motor. I would love to try it on an 18' boat but it is a risk that you would lose the handling of the boat you are used to.
 
Top