mv problems any ideas?

[amk]

I recently put a bigger motor in my jet went from a 650 to a 760 Yamaha. I had a issue with the boat shifting edges before when I had the 650 and ran empty but now it does it worse and even with light load its like the v is on the edge of being either in the water or out so maintaining control can get hard at high speeds the water will catch one side or the other and it with push the nose one way or the other so I constantly stear back and forth. Also my stearing is pretty loose I have to turn pretty far to get movement so the whole motion is exaggerated.

Im looking to change the stearing the type I have has a threaded conection with a ball quick disconnect. on either end. Teleflex is what everyone uses but the connections are different I'm hesitant to buy it because I don't know if it will work has anyone done been there done that?

Also more important is any solution to my mv problem to stop it from swaying other than just running loaded down all the time. My buddy mentioned like a skeg or keel. like maybe putting a piece of angle aluminum off center maybe a couple feet long toward the back?

 

[amk]

The boat

 

[ColtonS]

Does the boat feel like it is not biting the water and more or less just skimming across the top?

 

[amk]

yes

 

[ColtonS]

I had the same problem on a flat bottom that i built and it was mainly caused from overpowering the design but I was able to fix the issue. I've seen your build thread and I think your problem is from too large of a flat/smooth surface in the rear of the boat. I would definitely put some strakes on the back so that the front is not the only part that grabs the water. If you don't want to go that route or have already done it there are several different things you can do to help offset the problem.

 

[amk]

so by strakes you mean just some angle aluminum like I mentioned? do you think size and offset maters or can I just roll up to the weld shop and have them weld me some on in a random spot? Do you happen to have a picture of yours?

 

[ColtonS]

material: yes aluminum angle will work fine although it won't be the exact same shape as the factory strakes.
size: I would match them as closely to the ones that are already on the boat
position: butt up to current strakes and run the full length of the boat, if there is a middle one run it up to about 1ft in front of the intake

It might be more cost and labor effective to use other tactics by trying to get as much weight off the front and moved rearward.

 

[ColtonS]

so by strakes you mean just some angle aluminum like I mentioned? do you think size and offset maters or can I just roll up to the weld shop and have them weld me some on in a random spot? Do you happen to have a picture of yours?

I wish I had pictures of it and the one I currently have but I never new there were so many other people out there doing these jet conversions until today.

 

[amk]

well if you take some I'd like to see your boat and the strakes

 

[PSG-1]

Here's a video where I replaced the corroded center strake in a johnboat with aluminum angle. This should give you an idea:

https://www.youtube.com/watch?v=GvVoheTe0mw&list=UUHYpuGo2zvfQcgL2J7VdAqA skip to about 2:30 in the video to see it.

 

[ColtonS]

The attached pic shows how to position the strakes....but I just realized you have flotation pods which makes me think you might be to front heavy

 

[amk]

thanks im dreading pulling my motor so I can get my boat inverted to have it welded! but it will have to be done

 

[Ranchero50]

Does it seem to float when it's doing it or just banging side to side? Wind / wave conditions? Sorry, but your description of the problem isn't very descriptive.

My front end will float when running into the wind and get's sketchy running into the wind solo. Where are you seeing your side spray at speed? Going 45+ I see it out of the corner of my eye from my driving position, it's behind me. If yours is further forward you are nose heavy.

Strakes at the rear won't do much about the front moving around. I did weld a full length of 1" x .125" aluminum angle to my keel and it helps a good bit with the fork lift style steering. At speed I can run hands off or crank full steering input without any bad effects except the hull will swap ends once it bleeds off enough speed and water will come over the sides at the bow.