Ijust bought a 06 ranger 620 with a f250 on it and I cant get it to stop porposing. Iam new to the fiberglass boats so please bare with me. I am running a 23p. v-max prop and the only way to get it right is to run with the trim all the way down, all the way. If anybody has any ideas I would appretiate it. I am not using a whale tail yet, but might try it. Thanks Coondog

Don't have an answer for you but everyone is going to want to know what hole you have your motor mounted on.

Porpoising at WOT???

If you do not have it trimmed all the way down to start you'll porpoise! start out all the way down and thn just move upward until she just starts to porpoise and then bring it back down to stop.
That has always worked for me!

Coondog

Here is a couple of questions

(1) Does it porpoise between 3800 & 4500 rpm with the motor all the way down and if not will it start to porpoise if you trim it up.

(2) If you are over 4600 rpm, does it stop porpoising and you then can trim it up all the way with no problems.

(3) Does it porpoise more on rough water and if you speed up it quits

If this boat came from the factory the motor would be mounted all the way up with the prop shaft about six inches below the pad.

Bullseye, Thats what it doing ,3800-4500rpm, trimed all the way down, still does it. I havent ran it at WOT for very long , so I cant how it reacts to that, still pretty doggy on hole shot, thats why I was thinking of a lower pitch prop. I also checked where the motor is mounted, top hole. So what should I do to correct this? THANKYOU COON DOG

I'd pickup the phone and call Ranger before doing anything.

Put a 21p rev 4 and a fin on the motor and your problems will be solved.

Do a lot of you guys use fins/hydrofoils on your motor to minimize porposing???

I get quite a bit of porposing with my 215X/250 ProXS and have contemplated a hydrofoil, but I never hear anybody recommending them.

I have to agree with Dodge1. I wouldn't consider putting a fin on a 250hp motor. All you need is the right prop to make it run perfectly. Once you get close, you can have one of the experts tune the prop and do even better, but you need to find the right prop for your boat/motor/load first.

The reason the bout is porpoising is because you are trimming it out to fast. Once you get the boat to the desired speed you want to be at trim it out slowly till you feel the first sign of it wanting to porpoise, then trim it back slightly ,this will change as you increase or decrease your speed also you may want to start trimming it down before you start to slow down or it will porpoise again as soon as your speed decreases. If you don't understand what I am trying to say call me at 701-789-0886 and I will try and explain it better.

George

but have you checked to see that your engine can trim all the way in? The only reason I ask is that most engines have a series of holes on the bottom of the part that mounts to the transom and my last engine had a steel rod going through the set of holes closest to the boat. My current engine has the series of holes but it has no pin mounted in any of the holes. If there is anything keeping your engine from tucking all the way in, it could give you the symptoms you're getting.

Just taking a wild shot because even with all the weight in the back - F250, livewell, batteries, etc - I would think a 250 would have the torque to keep you running level.

I have an 1860 and a 175 opti, but I've been very impressed with the High5 as far as ride control. It's not going to win you any races, but I almost can't even make mine porpoise on purpose. (say that 3 times fast)

I agree with the others that you can most likely fix this one with the right prop provided your engine is firing on all cylinders.

or doesn't quite fix the problem, I would look at installing a couple of transom wedges. Install them with the point down. This will change the angle of your motor to transom and force the motor to drive from more beneath the boat. I've seen it work on Crestliners.