Jet convertion help

[Steven3]

I have currently been working on a jet jon conversion with my brother. The plat form for this build was a beat up 12' V-bottom aluminum boat and a Yamaha 650 wave runner.

We have successfully installed the jet in to the boat and have been able to test it in the water ways around the house. the issue that we are experiencing are

1- it is plowing real bad( as if the jet is trimmed into the too much). tried to combat that with offset bushings on the nozzle angling the propulsion upward. it did help a little.

2- when it starts to plow the boat hooks to the right very hard. you are able to steer out of it but you are fighting it allot

3- can only run the boat at about 1/2 throttle due to the listed above problems.


We are about to start another boat but don't want to end up with the same results. We are hoping that it is just a hull issue more so than a build issue.

 

[juggernot]

From the pic from the stern side it looks like the hull is twisted? If so that might be the cause of the pulling. I also assume jets perform/steer better on flat bottomed boats.

 

[He Reigns]

Aside from the hull issues, have you tried moving weight around to see if it changes anything?

 

[Steven3]

We have moved the seating arrangement and the gas tank is in the back. When we moved it to the back of the boat it helped out might have gained a few MPH on top side before it tries to put you back on land.

Thank yall for your input. We are going to continue tinkering with it might end up with something that will work.

 

[Ranchero50]

Most likely you will have ti figure out a way to change your nozzle angle so it's not plowing so hard. Some better pics (side and rear plus close ups) will help a lot. If your nozzle is plastic, you can screw on a soup can at an angle as a troubleshooting aid. Center line of thrust on the jet should be even with the bottom of the hull.

Your twisted hull isn't good either. You really need to twist it back true or you will end up with a Darwin award once that thing gets up to speed.

 

[He Reigns]

Pump level with bottom of hull, I need to remember that one. I have read that a "bit" of the pump pointing down is not bad either. Of course everything on the internet is true . This type of information is invaluable to me in my build, thank you.