Do you back off the throttle after your on the plane? Could be anything from hull design to weight distribution. Need more info to be able to make an assesment.

Tried that, but I dont get much of a reduction of speed B4 she boggs down. Then the whole process starts again. Just wondering if this is normal. Yesterday watched boats going pastme, the term wearing your nuts around your neck can't be far wrong from what I saw.

Being older I(we) just want a bit of confort.

Your trim & tilt should fix that, i have my trim up to take off then lower it to stop bouncing about.

You can alter your speed with trim & tilt. Try backing off speed once she bogs down and and increase your trim again until you get the desired comfort speed.

No need to bust your balls in choppy conditions

i would have to think its more weight distribution than anything else, can be fixed by installing trim tabs if you spend the $$$ or fix one of the large fins to the outboard leg which can give extra lift in the rear end at lower revs and holds the plane better ,  the other thing to assess is the motor to low on the transom or propellor size incorrect.

i had the same problem but fixed mine with the a change of prop and the weight distrubution as menetioned above

Once up on plane, trim bow up slightly and then lower rpm to suit. Move some weight forward.

If you can't solve the issue with the above, then;

As said, an outboard hydro foil would help lift the stern and hence the overall trim.  I bolted a set of aluminium foils onto my old tub (surfrider 19ft).  This made a significant improved difference to the trim and top speed.

A new prop would most likely help alot too.  Talk to Mike at Just props in Ossi Park for a recommendation. 

Cheers Pete

Gday mate,

Don't know the size of ya boat, mine's only 14' but I ended up takin my hydrofoil off because it caused cavitation when turning at speed, would definatly agree with talkin to just props.

Buy the way all, if you ever have the idea to go into seasport marine in Kelmscott, DON'T DO IT, don't get me wrong I'm all for supporting your local but they have no customer service skills or knowlage, after suplying me with throttle cables for a 75hp+ for my 30 merc (different fittings) I returned them only to recieve the advice to stick them in my ass, not sure if he thought it was lubrication issue but I don't see how that would help. Was forced to buy another set from foothills marine in Kenwick, the guys there even gave me a trade in on the wrong ones even though they would be hard to on sell, hopefully some leunitick fits a 75 to a 14' tinny.

What motor have you got, This problem can be caused by dirt in the carbys around the emulision tubes, Last one I did was a 50 Yamaha, did 12 knots or 22 no in between, Fully cleaned the carby's and proble m solvered!!

Sonny

Have a read of the thread on fitting hydrofoils, it might give you second thought on them. They are strictly a last resort and not a good option at that.

Sounds like your motor may be a bit heavy for your boat........this is why hydrofoils can help, as they essentially lift the back of the boat, simulating a lighter motor.

Some hulls are designed for lighter 2 strokes, and when you bolt on a big 4 stroke, the extra weight, together with the fact that 4 strokes tend to have less torque in the mid range than 2 strokes of similar power rating, results in the effect you have. 

Weight distribution and trimming should help, hydrofoils are a bandaid but may help.

My boat has a lighter direct inject 2 stroke, and is pretty light on the rear end (to  the point where it does want to broach in a big following sea which aint fun....). I dont have any of these issues and can run consistently at just about any speed 1 knot either side of where it planes at around 8-9 knots.