porpoising help

[merc01]

I have a 1994 bayliner capri 1750 with a Force 120. I use it primarily for fishing & tubing - not sure what prop is on it. It runs great with 2 or more people, but when i am alone, it will start porpoising when i trim it up @ WOT. I know i can get more speed out of it, but not sure how to stop from porpoising. As soon as i trim it down a bit, it corrects itself. I also have a "doelphin" on it. Any advice would be appreciated.

 

[78 GT-150]

Re: porpoising help

My little 15 footer does the same thing, it's not putting enough power to the water to keep the bow lifted. I do the same as you and drop the trim a couple clicks.

Keep playing with the trim and it will do what you want it to.

 

[ziggy]

Re: porpoising help

have ya tried it w/o the waletale?

if ya gotta have something for high bow rise or to get the bow down in general, ya might look into smart tabs. lots of folks like them..

fwiw, i can porpoise too. to fix it i trim down. i run nothing. no tabs, no tale.. when i start to porpoise, i figure i'm at the end of the performance of my hull and engine combo... my wot is right on at the high side. my speed is 42mph. prop slip is .10 which i think is good. not great speed by today's standards but i'm satisfied with it for they design of rig i run. my rig just ain't gonna be no speed demon. perhaps yours isn't either...

 

[merc01]

Re: porpoising help

i have not yet tried it w/out wale tail, but i don't have high bow rise - it planes almost instantly. w/1 person in boat i can run about 45-47 before porp. starts - w/ 2 people, i can trim up & run over 50 easily

 

[78 GT-150]

Re: porpoising help

Try adding some weight or repositioning weight to the front. It may help.

 

[dwhite1031]

Re: porpoising help

My 16 foot aluminum bass boat did the same thing until I figured out that I could add weight to the front (actually just past mid boat) by filling my livewell with water. Found out by accident when my 13 year old grandaughter sat on the livewell lid and the bow dropped and she smoothed out. It's a 16 gallon and @ 8.6 lbs per gallon of water, it gave me the weight I needed to stop the porpoising.