speed problems

[dixie420]

hey guys, i hope someone can give me some help with my boat. ok the boat is a 14ft dixie V hull. the engine is a 25hp johnson tiller steer with a 10/13 prop. when i take off in my boat it starts off fine, it planes out around 12-15 mph, and as long as i only hold it at half throttle everything is fine, boat runs about 20 to 23mph planed out nicely. my problem happenes when i give the boat full throttle, its like it pushes the front back down into the water, its still planed out, but there is an enormous amount of spray off both sides of the boat that isnt there when its at half throttle planed, thats not so bad, except the boat actually loses about 2 to 3mph running it this way, worst of all i have very little control over my steering, the boat starts to turn to one side and the only way i can get control is to let off the throttle. im assuming the boat wasnt made to go faster than 20mph, but im lost on this one, every boat ive ever had i could run wide open all day. ive tried moving around in the boat and shifting loads, adding weight taking away. what gives ? does the design of my boat just suck ?

 

[Spidybot]

Re: speed problems

You have to look over your motor trim setup.<br /><br />Your motor must sit in the exact middle of the transom, should have the antiventilation plate level with the bottom line and should be angled on the transom in a way, that the antiventilation plate is parallel with the water surface while planing.<br /><br />Next you should look over weight distribution in the boat.<br /><br />These things ought to be a good starting point,

 

[magster65]

Re: speed problems

If it's older or weak there's a good chance it has a 'hook' in the hull. My brothers old Campion had the same problem.

 

[dixie420]

Re: speed problems

magster i think you might be on to something, the boat is a 65, and the bottom is rather flexible when your moving fast, UU thanks for the advise, but my motors anticavitation plate is perfectly level witht he water when the boat is planed, also when i try to trim the motor up the problem happens at a slower speed, also if i trim it up the whole way it has the tendency to start cavitating at high speeds. i guess fix the bottom is the only cure for this. well the boat is old ill probably just run it this way until it sinks, thanks

 

[Jdeagro]

Re: speed problems

To Dixie420;<br /><br />Do you have a hydrofoil on the motor? The faster you go the more lift they give, and at cruising speed you do not need that much lift.

 

[DJ]

Re: speed problems

dixie,<br /><br />You are "plowing". Adjust the trim on the engine up (engine out) one notch at a time. You do this by lifting the engine, remove the pin and reinsert it in the next furthest out notch.

 

[TELMANMN]

Re: speed problems

Djhons might be on to something. I was leaking a small amount of water so after my boat sat for awhile the first time out I would plow water with the same trim setting that I normally used with just me in the boat. If I adjusted the motor trim It would run well. I would then pump the bilge to get rid of the water that I got from being up on plane. After doing this a couple of times I would then reposition the motor and have no more problems.<br /> Sometimes it is just the easiest things that make a difference. I found the leak from the live well pump, repaired and then no problem.

 

[catfish1]

Re: speed problems

djohns19 is absolutly right! i have a 17ft dixie, and i had the "exact" same problem. anything over 20mph and it would lean over and it wouldnt steer, the only thing i could do to correct it is slow down. <br />if you ventilate when you tilt out, it is possible you may have to lower the motor a little (x dimension).

 

[magster65]

Re: speed problems

Dixie, It's often overlooked. A tiny hook is all it takes. We glassed in some plywood gussets to stiffen it up (running lengthwise at the transom). It worked. He gained a bunch of stability and could go w.o.t. then.<br />I'm not sure why we bothered though, his boat was a real beater...