Need ideas to stop porpoising? - Page 5

gss036 · #41 08-13-2008, 08:43 PM

Went fishing yesterday(did not say catching,bad day, 3 dog fish and 3 lingcod,ling cod is closed). The lead is out and the boat preformed great. Now to work on the prop, I was able to run it up to 6000 rpm/44mph/GPS and still just a touch of throttle left. RPM range is 5000-6000 rpm, I am trying to get them to swap out the prop for a 4 blade as suggested above.

Fr. Frank · #42 08-14-2008, 12:51 AM

You want to be able to hit the upper end of maximum recommended with the boat at max gross weight. Load it up with full fuel, max people, and max equipment, and you should be able to hit the upper end of max rpm range.

You should be able to hit max of max at max.

I can hit 5800 rpms with full fuel and 7 people on the boat, along with beach and camping gear in the cabin. I expect to never spin a hub from overloading, or have a shortage of low-mid-range power/torque in an emergency.

gss036 · #43 08-20-2008, 06:02 PM

Went down south and picked up my new 4 blade prop this AM. Just installed it and hopefully will be able to get out tomorrow or Saturday. I am anxious to see how it performs compared to the 3 blade. Talked nice to the dealer and he ended up taking my 3 blade prop back and we split the difference in the price on the 4 blade Powertech.

gss036 · #44 08-23-2008, 03:41 PM

Well, now I am satisfied w/the preformance, no more porpoising. Got the new 4 blade prop installed and was able to run it yesterday. I can tell the difference in the handling, especially in the no wake zones, also jumps up on plane fast and lifts the stern up. I was able to get 5900 RPM , just had the motor trimmed so top of the motor was level w/the water. It looks like I am going to be getting between 7-8 GPH at moderate speed of 28-30 mph @ 4000 rpm. Now I am really a happy camper. I also had an outstadning day fishing, caught the largest salmon in my life for me. My scale quits at 40# and it still needed more, somewhere around 45#s.

Bushwacker · #45 08-23-2008, 11:00 PM

Good deal - sounds like it might stay on plane at a lower speed also. If running in flat water, you might be able to squeeze a little more max rpm/mph out of it with trim adjustment. Most folks trim out until it either starts to porpoise or the prop ventilates, then trim down just enough to stop that. This will minimize hull wetted surface and drag, but won't be the best ride! Trim tabs should also be all the way up for max speed.

gofastsandman · #46 08-24-2008, 10:30 AM

Sounds like someone is having a really good day.

Isn`t it amazing how much a prop can affect attitudes. Yours, the boat`s ,and even the fish are excited! Now go buy a bigger scale!
GFS

Briguy · #47 08-27-2008, 10:54 PM

Hey great news. Now let's see pix of that monster. 40+ pounds???????? Did you smoke it or just filet it out and share it with your closest dozen neighbors? I'll bring the bagels and capers.

Fr. Frank · #48 08-28-2008, 09:23 AM

Quote:

... I'll bring the bagels and capers.

Brian, you have got to learn to catch your own fish someday

gss036 · #49 08-28-2008, 02:00 PM

[image]http://http://i44.photobucket.com/albums/f4...6/DSCN0422.jpg[/image] Maybe this will tranfer. Didn't transfer but at least you can look here. I managed to do this a couple weeks ago, guess I am having a senior moment.
[image]http://http://s44.photobucket.com/albums/f41/gss306/?action=view&current=DSCN0422-2.jpg[/image]
I had to click on the img code to finally get it to transfer, hey! only took me about 30 minutes.

gss036 · #50 08-28-2008, 02:38 PM

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