Jet boat

I am building a rear deck in a jet boat that was gutted by a previous owner. It is a 16' tracker with the stick steering up front and has a Merc 30/40 jet motor. I am planning on making the deck so that the batteries and gas tank can go underneath it, should I lay it out for 2 5 gal. tanks or is one tank enough for a day of average running on the river.
Thanks in advance!! Doug Lindsey

Since you have stick steering in the front.....I would definitely have 2-5 gallon tanks back there. Filling them both can be a "game time" decision depending on how long your runs will be BUT at least you will have the capability of filling both of them if you are alone. With that size engine and boat size, weight will be a huge factor for you in getting through very skinny water.

Set it up for both thanks for sure!

I like one full tank and then 1/2 or less in the second tank just in case. I run through a tank many times and needed just a tad more out of the second one.
Off set you weight by putting the full tank on whichever side you need weight to be perfectly flat.
2 full tanks are not needed and are extra weight, but one sometimes doesn't cut it.

I do remember a day that my tad wasn't good enough and Red drug us back in as the wind upstream was stronger than the current and the trolling motor wasn't enough to buck it either.

thanks guys!
my original plan was to put a battery on one side and the gas tank on the other side, I figured that would keep things pretty level since the driver seat is in the middle up front. Then a guy at our last club meeting told me to be sure to carry 2-5 gal tanks with me so I thought I would put a tank on each side and the battery in the middle in front of the motor. Also, I might add that I have a 24v minn kota on the bow and battery #2 is going to be under the driver seat, since I am small the weight up front shouldn't be too bad.

I went with the largest motor lb thrust and still be on a 12V system to cut on another batteries weight. It's a minkota 55 lb and bucks most anything that you should be fishing.

If yours ever dies maybe think of going that route? Until then I'm sure you'll use what you've got.

Doug,

Does that 40/30 push your boat pretty well?? Is your boat a flat or does it have a slight pitch in the hull?

it seems to push it ok, I only ever had it on the water once at a local lake to see how the motor ran and to be sure all the wiring and controls that I had to put in worked ok. I think I got 27mph gps out of it. I am pretty sure it has a completely flat bottom with no rise at all.

27 is very good.....sounds like your boat is balanced nicely to achieve that speed. You will love the stick steering in the front when running skinny. If you have the extra money, go ahead and order an extra intake shoe.....if you wait until you break it, it might take you 6 months to get another one. They are all made by the same company in CA. During the summer months they sell out and cannot make enough of them to keep up with the demand. They used to cost around 300-350 bucks but I have heard Ebay has them a little cheaper. They also make a HD plastic intake shoe that is pretty much indestructible for about the same price.

My first jet was a 25/20 on a 14ft. flat bottom. I did not get anywhere near 27 but I sure could go shallow and that was the goal. I made my rear casting deck and flooring out of 3/4 treated but did not permanently secure the deck or flooring to the boat. If I was hauling a client or another guy (and gear) I would pull the deck and flooring out, when running very skinny water.

Ok thanks!

Have you ever used any thru hull transducers for this kind of set up? I figured it would be best rather than having a regular one hanging down to catch on something and snap off. I know someone who also said you can use a regular transducer inside the boat as long as you encapsulate it in silicone?? Any ideas on this? I have a lowrance x-15 with gps I am thinking about using for a locator.

I have always just pulled the transducer to that only the bottom 1/8 of an inch hangs down. Keep the setting just tight enough to keep from kicking up when on plane but loose enough to kick-up when you are drifting through shallows and hit something. Still works for trolling because the boat is sitting 7-9 inches lower that when on plane so it is not and issue.

I have never had a thru-hull with my river boats.

a good thing to keep in mind about fuel too...

around 70º gasoline weighs about 6.2 - 6.7 lbs per gallon, depending on what source you get your info from !

in lower temps, i've read that gas weighs more.

as a general though, i go with 6.5lbs per gallon. 5 gallons being 32.5lbs if my math is right.
10 being 65lbs obviously, and so on.