FS14 feels like it's wagging it's tail a little

[BradleyD]

I've just my FS14 going and trying to get everything dialed in just right. When running in a straight line it often feels like it is trying to break loose and drift back and forth in the stern. It is not severe and nothing that even needs correction from the motor (once it feels like it drifts slightly it comes right back) but it's there. Seems kinda strange having a skeg installed and even when I try I can't make the boat actually break loose and slide. In fact the boat turns like it's on rails and at speed it can just about turn around inside iteself. The boat doesn't feel unsafe when it happens but it's there and would like to get it corrected but really have no idea what could be causing this. I thought maybe the skeg was not installed straight but it's as straight and square as I can possibly measure on the boat and if it wasn't square it would seem that the boat would want to track in one direction or the other...but I could be wrong Any thoughts?

[Evan_Gatehouse]

Try tightening the clamping bolt on the motor that determines how much friction is required to turn the motor. If it is too loose, the engine will always try to turn the boat to the right and it might feel like you are describing.

[BradleyD]

The friction adjustment is probably at 80% at least. I prefer to keep it on the tight side. That being said I will check everything out to make sure nothing is loose or worn that is allowing the engine to have a little movement. Hopefully soon it will have a new motor on it anyways. Thanks.

[tech_support]

how fast are you going and where is everyone sitting?

[jacquesmm]

Once the mechanical side is take care (see Evan), as Joel writes, it can be trim.
There is an attitude in which at some speed, suction can develop close to the bow, forward.
Does the boat heel when that happens?
Anyway, lets us know what the speed, load and trim is. Engine HP too.

[BradleyD]

Once the mechanical side is take care (see Evan), as Joel writes, it can be trim.
There is an attitude in which at some speed, suction can develop close to the bow, forward.
Does the boat heel when that happens?
Anyway, lets us know what the speed, load and trim is. Engine HP too.

Checked the motor and nothing seems out of the ordinary as is on the trailer. The motor is a Merc 9.9 four stroke and total weight is probably around 750lbs max with myself and a couple gallons of fuel in the back and battery, small cooler, and misc gear in the front. Speed it is occuring is from around 13mph up to 20mph. Probably the worst around 16-17. After using the boat some last weekend I knew my trim wasn't quite right with too much weight in the rear so I spent a couple hours yesterday afternoon at the lake adjusting the motor height, trim, etc. to get it the best I could. Motor height has the antiventilation plate approximately 3/4" above the bottom of the boat. I also installed a small hydrofoil that helped the trim tremendously where the boat rides just slightly bow high and one notch down on the motor can push the bow down just slightly. The condition is still there before and after all of the adjustments.

Do you mean "heel" as in the boat slows down? If so then no, the speed does not seem to change.

[jacquesmm]

Probably too much weight in the stern (back).
When I am alone in a boat like the FS14, I steer from the middle seat with a tiller extension. A tiller extension is a piece of PVC pipe over the outboard handle.
You will get on plane faster, go faster and the boat will be more stable.

This is not specific to the FS14: all planing boats require some weight distribution.
If you want a rule of thumb, try to get the center of gravity forward of the transom by about 40% of the waterline length.

[BradleyD]

Thanks, I'll try that next.

[BradleyD]

So after getting to use the boat much more since my last post I have got to use the boat much more and the problem still exists. I have distributed weight and adjusted the motor (which is now a 15hp Yamaha 4S) and nothing solves the issue. I sit in the center of the boat with the only real weight in the stern is the motor and 3 gal fuel tank, everything else is in front of me. It has become a real annoyance not knowing what is causing it. I've never felt a boat do this before and feels like someone is kicking the back end of the boat back and forth randomly. It is not enough to be a safety issue but it definitely seems to hinder the performace when it happens. Below are two videos that I took to the best of my ability being by myself. It's hard to get a sense of the effect by the videos since you cannot feel it. The video looking forward you can see the bow moving as the result of the "kick" in the back. The video looking aft is hard to see any affects but look at the disturbance in the wake coming off the boat. When it "kicks", it kicks the wake and prop wash too and almost looks like I may have run across a small wake from another boat. You can see this best right at the end of the aft video after I make a small turn then the video stops. Also, the boat seems to throw an unusual amount of splash out of the sides and torwards the stern as if it is not cutting cleanly through the water which I have a feeling may be related. This may be hard to see since it was hard to back away far enough to see the entier stern. And back to big question...what in the world could be causing this? I have triple checked dimensions and straightness but all looks well. What kind of mistake could I have made that would cause the hull to act like this? I'm thinking about adding spray rails for the side spraying but almost feel like it may be a band-aid to the real problem. If I built the hull correctly then the only issue I may see it to be is the skeg, which I was thinking of removing as well to see if the issue goes away. Thoughts?


http://youtu.be/NtWQgSQUfVA


http://youtu.be/c-Sz9MUjaqo

And Happy Thanksgiving!

[Heloman78]

Would you say it feels like it starts to crab a bit than kicks back straight?