porpoising 116 ranger cherokee

[jtrbug]

Need help with 116 ranger cherokee to help eliminate porpoising. Boat has a 60hp mercurcy with t/t and 10/13 stainless prop. Cavitation plate is even with keel when motor is zero trim and boat level. This boat is flat across most of the keel and is 78" wide, no pad, basically a flat bottom. It really starts to hop when trying to run with bow up at wot. Have already put on a 300se sport stabilizer and had some success. Picked up better hole shot and stayed even on MPH. Motor is mounted to transom in center holes of motor mount brackets. Could move motor up or down but which way? Don't have a jack plate yet. Any help would be appreciated.

 

[DJP]

Re: porpoising 116 ranger cherokee

Movin the motor down about 3/4 inch would allow for further trim in obviously, which MAY resolve the problem, but ultimatly the Jack plate is the answer, you might as well bite the bullet and spend the $$$$$ on it.

 

[jtrbug]

Re: porpoising 116 ranger cherokee

Thanks Trippin' for your reply. I think you're right. I'm going to position the motor as far down on the transom as I can. That'll move it down about a 1-1/2". I've never had much trim adjustment and usually have had to operate boat at wot with as much negative trim as possible. That will put my cavitation plate about a 1-1/2" below keel.

 

[Silvertip]

Re: porpoising 116 ranger cherokee

Leave your engine mounting where it is. Visit the Nauticus.com web site and check out Smart-Tabs. Then get rid of the engine mounted fin. The Smart Tabs are about $150 (varies with size) but they solve a bunch of boat performance and handling problems. They are widely used, including on my boat. Plane at slower speeds, better hole shot, more stern lift, and no disadvantages.

 

[gonefishie]

Re: porpoising 116 ranger cherokee

Hey jtrbug, you and I are basically neighbor if you're still around BSU.

 

[txswinner]

Re: porpoising 116 ranger cherokee

I put smart tabs on my ranger, eliminated long hole shot and no chine problems or porpoising in flight.