16ft polarcraft help jet bound

[Nlawson0017]

i have a 16ft polar kraft that is basically a 16/48. mod v. Before i go wasting a bunch of time and money i would like some advice on what to do and what not to do. i was planing on moving battery's to the bow and moving the console about 2/3 to the front. stuffing as much flotation foam as i could get under the floor, in the bow and in the side panels. looking at a 50-75hp jet. depending on advice from people who have first hand experience.

is the boat wide enough to be a good jet candidate?
motor suggestions?
any other suggestions.

anything will help
the boats main purpose is to get me as far down the licking river (fishing gets better the further down u go) gets pretty shallow in the riffles.

thanks in advance

-Nate

 

[MjinPa]

Yes the boat is wide enough to get by assuming its the typical deadrise of a modified v jon boat it should work. A 50/35 or 60/40 should work fine. Weight distribution means everything. If u can put batteries up front, definitely do so. It makes a huge difference in getting the boat on plane quickly.

 

[rockdamage]

I just rigged a 60/40 merc 4 strk on a 16/48 alweld .100 gauge
boat ran 31 mph with one man which is a little slow
back of the seat measured 40" to the transom
your best options......

new 1. merc 40 jet 4 strk cheapest- most power
2. tohatsu 50/35 ....lighter but uses the medium pump
3. 60 etec jet ....long shaft --- oil mix--- pro's - decent power but pricey

used - short shaft 3 cyl 60/40 merc best choice !
https://www.ebay.com/itm/Clean-1997-Mercury-45-HP-2-Stroke-JET-Outboard-Motor-/390656141682?pt=Boat_Parts_Accessories_Gear&hash=item5af4eba972&vxp=mtr

40 hp omc ...lighter medium pump
yamaha 40 hp jet

 

[Nlawson0017]

Thanks guys. I'm deffilinty moving the batteries but I've got room to move the fuel tank up as well but was wondering when I get below half a tank if sucking air from waves will become a factor. Thinking about fabing up a custom fuel tank for the bow and inserting some foam in thank to help with sloching (same stuff I used in my drag truck) may add a sump to pull fuel from the bottom of the tank. also is there any difference in the jet outboards compared to just buying a regular prop job and waiting for a jet unit to come up on eBay that fits it.

Here's the motor I'm thinking I'm goin with. 84 70hp and picking up a jet unit for it. Bad thing I need the jet unit so I can start the tunnel and Build my tunes as big as I can and not have clearance issues.

 

[rockdamage]

Why are you running a tunnel??????

 

[Nlawson0017]

My boat has a ribs (keels)on the bottom that run the whole length of the boat so I was goin to remove the center rib about 3 feet from the transom and. And since I was going to be doing that why not just make a small tunnel to help feed and protect the jet drive foot. I was thinking of going to the keels on each side of center one I removed and using them as the tunnel width and just recessing it up about 2.75 inches and about 2.5 feet from the transom.

What's wrong with tunnels? All info is appreciated.

 

[rockdamage]

Cost you speed... feeding the jet is a myth. Getting a tunnel correct isnt easy nor is it worth the trouble. The juice aint worth the squeeze

 

[Nlawson0017]

The thing I'm having a problem with is the right shape of a tunnel. It's hard to find a straight answer.

Should the tunnel be wider at the front and funnel in smaller towards the transom? And if so about how much if we're talking a 3 foot long tunnel?

Will a recess of 2.5 to 3 inches from the bottom of the keel be enought or not enought. And the sides of the tunnel, should they go straight up towards the roof of the tunnel or angle in towards the roof of the tunnel.Ill post pictures of what I'm thinking when I get home.

 

[Nlawson0017]

rockdamage » 11 Sep 2013, 12:43[/url]"]Cost you speed... feeding the jet is a myth. Getting a tunnel correct isnt easy nor is it worth the trouble. The juice aint worth the squeeze

I was typing when u answered. Maybe I will hold off with the tunnel and see how she acts. Are pod or tunes worth it to help with the heavy motor? Boat sat a little deeper in the water in the back with a 28hp I can only imagine with a 70

 

[rockdamage]

Pods are ok as long as they arent wet when the boat is at speed

 

[Nlawson0017]

So I'm assuming you don't want them flush with the bottom. I was going to make them. I was going to make them flush with the sides of the boat and bottom of the boat and extend out about 2.5 feet and as wide as I could go with hitting the jet when turned left or right.and the height I have no idea about

 

[rockdamage]

The less wet area the better.

 

[RiverBottomOutdoors]

Sponsons/pods/toons, whatever you want to call them, increase drag. But, they can help with squatting on the whole shot and draft. Tunnel increases drag too, but it offers protection for the foot. The sole purpose of the tunnel is to protect the foot...that's it...has nothing to do with pump performance or feeding water. Adding either one to your boat may cost you 1mph on the top end.

 

[Ranchero50]

Having the pods help holding the rear of the boat up on plane will be worth any loss of speed. When I added mine I originally stepped them 1" above the hull bottom and that really screwed with the wetted CG. I had a lot of porpoising issues and ended up making full sized trim tabs to make up the difference. The results are a hull that launches flat and come off plane flat, two very important things if you are dealing with skinny water. I did go from 50ish MPH to 45 or so but the difference was well worth it.

If I were the OP I would rig the hull with the intake flush with the bottom and test it out. I don't think I would do a tunnel first, maybe a spoon to help push the air out of the intake path and load the jet correctly. The intake fins work wonders for hard turns and other rough conditions.

 

[rockdamage]

No need to remove the center keel any more than 18" ahead of transom.

 

[rockdamage]

How much is the 70hp omc ? It looks like it doesn't have power trim. And is it a 15 or 20" motor.
If im correct that engine is a 49cid engine

 

[Nlawson0017]

Well he has the power tilt and trim with it just off another one.And I was going to trade him my 1996 28hp Johnson with out power tilt/trim

I'm all ears.

You thinking I should sell the motor and buy something newer or what u segested. I was thinking I would like to have 50ish hp at the jet for the big river long runs when bow fishing.

 

[smackdaddy53]

Im rigging a similar hull with a 45 merc Jet. Its a 60 powerhead with 3 cylinders. The hull is a PolarKraft 16x52 with sponsons and yes it will have a tunnel.