Jon boat flip

[JSmooth33]

Been boating for years, mainly inshore fishing, and moved to Georgia recently and purchased a jon boat (my first flat bottomed boat).

Had an interesting experience I wondered if anybody else has had, or can comment on.

Boat is a 12' tracker boat with a 1998 Johnson 4stroke 8hp. I purchased the boat used and I can say that this motor is probably too heavy (Coast guard plate says 6hp max, and I imagine that is with a lighter 2 stroke).

Anyway, because of this the boat is fairly backheavy but with two people in it and the motor trimmed all the way in it planes ok and handles fine.

HOWEVER, I decided to take a spin solo for the first time with the motor trimmed all the way in. At full throttle I felt I was barely touching the water at all, and was screaming along. As I was trying to make a high speed left turn though, I felt that it was not turning/handling very well, felt like it was almost skidding instead. Then WHAM, I think the right edge caught, and I roll 45 degrees to starboard, take on 30-40 gallons of water over the side in an instant and almost fall out. I would have sunk if I hadn't given it full throttle and made my way to shore at 5mp with the bow 6 feet in the air and the back full of water to beach the boat.

Am I just an idiot for thinking that a flat bottomed boat should be able to turn at high speed? Or do you guys think this is a symptom of a my trim setup/too much motor. Suffice it to say I will NOT be making any high speed turns in a flat-bottomed boat ever again.

Thanks,
John

 

[Huron Angler]

Re: Jon boat flip

I think you hit the nail on the head when you said:

I can say that this motor is probably too heavy (Coast guard plate says 6hp max, and I imagine that is with a lighter 2 stroke)

Probably overweighted by the heavier 4-stroke, and the low sides make it easy for the water to bite into it on a turn. I have a 12' semi-V with a 5.5hp and I really wouldn't want a 10 or 15 on it since I restored the boat for my nephews and sons to use down the road and I don't want them having these kinds of issues.

Is it a shortshaft? I'd keep the motor and upgrade to a 14' rig, maybe a V-hull with higher sides, then no problems like this. Good luck to ya

 

[tashasdaddy]

Re: Jon boat flip

well the boat is over power and over loaded on the transom. the 8 hp 4 stroke weighs 30-35 lbs more than the recommended motor. you load distribution is horrible. it is an accident waiting to happen. and high speed turns in any boat can be dangerous.

 

[JSmooth33]

Re: Jon boat flip

It is a short-shaft. Also, I moved the gas tank+battery up forward which helps with weight distribution.

I am thinking about selling the 8 and getting a 5-6hp 2 stroke, but I hate to do that since I just tuned it up the 8 and got it running like new =/

 

[dash_riprock]

Re: Jon boat flip

I bet if you stored an anchor or two up front you could upgrade to a V-4.

 

[mphy98]

Re: Jon boat flip

GET A SMALLER MOTOR!!! In my youth (when I was 15) I flipped a 14' john boat with an old 5hp motor on it, It was rated for it but way to much motor, I took a turn into a wave too fast, and I was in the water quicker than you can say Jack Robinson. Broke the rods on the motor, and I could have been killed. Never again will I take out a john boat with a motor near the capacity.

 

[Home Cookin']

Re: Jon boat flip

I have a flat-bottom 19' carolina skiff--first year made. 50 HP so within capacity. Bottom is perfectly flat except 2 chines long each side, about 1 1/2 to 2". When you make a turn on a plane at good speed, it will slide and then suddenly grab, throwing everything from one side to the other. I won't replace the boat b/c I know this limitation but it is something to account for. The jon boat probably did the same slide and grab. The newer skiffs i think have this addressed somewhat. Point is, even bigger boats can act up.

 

[mrdancer]

Re: Jon boat flip

Suggestions:

1) Get a lower HP motor.

2) If you stick with a small boat, get one with rolled chines (like the mud motor boats) - they stick much better in corners.

3) Floatation pods on the transom will help with fixing the attitude of the boat with regard to weight distribution and add buoyancy/safety, but will likely not cure the "catching water" problem.