need advice moving motor

[deltaguy]

OK Ive cleared the deck of my pontoon took out all the furniture railings and carpet{glue was a pain in the a@@ to remove} and after thinking about it to make more deck space i was wondering if i can move the motor back so i can make use of the full deck..
right now the rear of deck has a v shape and motor sits in 2 ft with gas tanks on both sides..
what i would want to do is move it all way back and have a full deck that will add about 3 more ft.
my concerns are to much weight in back causing the front to rise..
the boat is 18ft with 40hp the way it was originally set up i only had 15 ft of deck space the back had a cover or platform over the motor and gas tanks..
i can do most fab work including welding aluminum and sheet metal work..just don't want to make a big mistake with moving motor and having a messed up balance in ride.
i will try to get some pics of what it looks like now below is a pic before it was all torn down..THANKS IN ADVANCE ANY FEEDBACK WOULD BE GREATLY APPRECIATED

 

[5150abf]

Re: need advice moving motor

Balance would be the least of my concerns, keeping the motor attached to the boat would be #1, by the way, I don't think that will make a huge difference in your balance.

We offer an extended transom on our boat so it can be done and you aren't working with a super huge engine(we go as much as 150 horse) so that helps too as does being able to weld.

By moving that back you are taking away the front support for the motor pan so you will need to really beef up the remaining ones.

Our motor pans are close to 6' long though so we have alot to work with, it depends on your pan, get up some pics and we will try to sort this out, I love a good engineering challenge.

 

[deltaguy]

Re: need advice moving motor

can you pm me you contact info thanks.
i got this idea from another pontoon that is parked next to me in the marina.
his motor pan and motor extends about three ft from the back of the boat.also noticed his gas tank is built into the pan.that would solve alot of problem if i can get the gas built into the pan.

 

[Jeep Man]

Re: need advice moving motor

My '88 pontoon is like yours. My new one which is an '08 has the motor 2 ft. behind the rear of the toons. With the deck off, now would be the time to weld in supports and move the tub back. I would run your design changes by a knowledgable marina before starting. I would like to see before and after photos if you get the thumbs up.

 

[deltaguy]

Re: need advice moving motor

here is what it looks like now..
question what does a new pan that i would need with a gas tank built in cost?
can i use my existing pan and just move it back?

 

[5150abf]

Re: need advice moving motor

From the pics it looks like you should be able to get this done.

You will need to find a cross member or something else to put across the back, if you are eliminating the cut out you can span that with a cross member and you are just moving the mount back without losing any support.

I would make the back one super beefy as it will tak ethe most stress.

As to the gas tank, I don't know about that one, th pan looks pretty small so I don't know that yopu could get enough of a tank in to be worthwhile and that may upset your balence having both the motor and gas hanging off the back of the boat, I am sure there is a battery in there as well.

Not to mention all the vibration, aluminum cracks anyhow and when you throw alot of vibration on it it just accelerates the process.

My proffesional opinion is you can move the pan back but I would keep the gas on the boat for both weight and safety.

Oh, and to have aweld shop fab a gas tank would be upwards of $300-$400 probably.

 

[deltaguy]

Re: need advice moving motor

so do you think i should go with the pan that i have now or buy a new larger pan that can hold a gas tank. if i keep the pan i have now are there gas tanks available that can be mounted on the deck safely and out of the way ?