[RiverSide7]

i have a friend who runs a white-knot tunnel, and its a very mild tunnel. its an extremely well built boat, and he has a 140 suzuki jet. he gets some cavitation and he hates it...so he put on splash guards and the whole nine yards and it made zero difference. The guys that make the jet lower units can send you a brochure on why to not run jets with tunnels.

 

[fish-on-a-stick]

Then what is the purpose of a tunnel?

 

[fish-on-a-stick]

Here she is!

 

[RiverSide7]

tunnel hulls were designed to be used with a prop, not a jet...

 

[fish-on-a-stick]

I all the reading that i did online said that certain tunnels are designed for use with jets

 

[RiverSide7]

white-knot is a tunnel designed to be used with a jet and it still cavitates. and they are in my opinion one of the best boat brands out there

 

[hotrodderscott]

I have a std. 20" transom. I am looking for a new motor for the boat and have been back and forth between a prop or jet.
To get the performance I am looking for a believe I would need at least a 90/65.
My question "Soog", what is the difference between building up your transom and running a jack plate???
If both of them hold the lower unit in the proper location what is the difference???

Look up www.jetdoctor.com call him and ask him all your questions.
He helped me alot..
I also started out with a jackplate because when I es having my boat built I didn't know I was homna run a jet.
HORRIBLE idea.. 2 weeks ago I removed the jackplate and raised my transom. It performed 100% better, fuel milage,speed, everything improved!

 

[SOOG]

The jackplate will cause a enormous amount of spray..the water will tunnel up through the jackplate and spray water into the boat.. So then you will build several different spray plates... The one that works best really won't work that great.. Also the water will hit the side of the jet and cause spray..you can't trim your motor at all bc it will spray even more. Also the jet seemed to be deeper in the water at full plane..so I wasn't able to run as shallow.. When you suck vegetation up in the jet it is that much further u have to reach. Also I lost speed with the jackplate.. Now with no jackplate I have ZERO spray. When I'm at full plane the foot is all that's under water. I have gained speed and can trim the motor to get that little extra. All I need was buy a piece of 1/4" aluminum and bolted and welded it to my transom. Not really that much work..it is worth your time to raise your transom. You will save Tylenol and time. There are prob more benefits than I have mentioned but I have only been out 2 times since I did this.i will have my boat out sat morning and have plenty of time to get a feel for it..

 

[fish-on-a-stick]

Ill post some pics of my jet, transom, and tunnel.

 

[hotrodderscott]

Thanks for the info Soog!

The jackplate will cause a enormous amount of spray..the water will tunnel up through the jackplate and spray water into the boat.. So then you will build several different spray plates... The one that works best really won't work that great.. Also the water will hit the side of the jet and cause spray..you can't trim your motor at all bc it will spray even more. Also the jet seemed to be deeper in the water at full plane..so I wasn't able to run as shallow.. When you suck vegetation up in the jet it is that much further u have to reach. Also I lost speed with the jackplate.. Now with no jackplate I have ZERO spray. When I'm at full plane the foot is all that's under water. I have gained speed and can trim the motor to get that little extra. All I need was buy a piece of 1/4" aluminum and bolted and welded it to my transom. Not really that much work..it is worth your time to raise your transom. You will save Tylenol and time. There are prob more benefits than I have mentioned but I have only been out 2 times since I did this.i will have my boat out sat morning and have plenty of time to get a feel for it..

 

[bowfishin bill]

I have no problem with water intake oh wait I have no problems with the boat at all. I love the pump if its below the surface its not a problem. Fished with a old friend last weekend after running in 4' of water he looked at me and said just think off how mint more fish we could have if we had this boat 5 years ago. View attachment 22460

 

[Jake Rife]

I have an 1860 Fisher with a 90/65 jet and had 6 men, 2 dogs, and decoys and was able to still get on plane. It's all about moving the weight around to get up and move around to still run. I wasn't able to run in 4" of water with that kind of weight but I've ran in 3" with 3 people and still not touch (trimmed up with weight forward).

 

[herpin1579]

I'm pretty sure the tunnel on those lowes were designed for jets