Moderated Discussion Areas
ContinuousWave: Whaler Performance
|Author||Topic: Turbo-Lift hydroplane|
posted 04-12-2001 06:16 PM ET (US)
Has anyone had satisfactory experience installing one of these bolt-on plainers onto an outboard motor lower unit?
I have a 91 Montauk with a 90hp Yamaha, runs like a scorched witch, but does not plane at lower speeds, which is more important than top speed.
Thanks in advance for any replies.
posted 04-13-2001 06:03 PM ET (US)
If you go back in the threads there are many members that swear on doel fins. My guess is that you will benefit form them, a 30 minute task to install.
posted 04-13-2001 08:26 PM ET (US)
I'm surprised that anyone is having planning problems with Montauks. I have one with a 50HP four stroke and it pops up on plane.
Previously I had a Dauntless 17 with a 125HP and it took forever to plane.
At 10MPH I'm still on a plane. Maybe my expectations are too low. Don
posted 04-14-2001 12:16 AM ET (US)
My venue is the Delaware Bay which at a minimum, always has a 1 to 2 ft. chop.
I would like to plane at 15 mph if possible.
posted 04-14-2001 07:55 AM ET (US)
Ts, I'd work with your Yamaha dealer to re-prop it with a more efficient prop, perhaps a 4 blade SS. Only as a last resort would I install an aftermarket foil / fin device.
posted 04-14-2001 11:10 AM ET (US)
I too run a Montauk with a 50 hp 4 stroke. I have never checked time to plane or minimum planing speed but it gets there quick. Am running a 13 pitch Merc SS 3 blade.
posted 04-14-2001 05:43 PM ET (US)
Dick, I running a Merc Vengeance SS prop, 11" dia X 12 pitch and I get full 6000 rpm; assuming the factory tach is correct. Don
posted 04-14-2001 09:57 PM ET (US)
I am installing a new Teleflex 7K tach and going to make a run before I make any changes. I probably will have the prop re-pitched to 12 but I also want to try the motor up one more hole. I'm happy the way it is but if I can perk it up: Why not.
posted 04-15-2001 11:38 PM ET (US)
Definetly install the Doel-Fin. I have a 17' with a 90HP. Your right about top end speed.
I had the same problem as you..... in a 2 to 4 ft chop (Gulf of Mexico) It would beat me to death.
No problem planing the boat with a 90hp, just minimum speed to maintain plane is about 25 mph (too fast in choppy conditions for me. I installed the Doel-fin.... perfect.... I can maintain plane at about 15 mph.
My suggestion is to do it. There are several links about this subect... and the "experts" are on record endorsing the Doel-Fin.
posted 04-16-2001 12:24 AM ET (US)
Thanks Chris; Was leaning in that direction, and after reviewing all of the endorsements in previous posts, I'm sold on the idea, and will order one.
posted 04-16-2001 01:59 PM ET (US)
Remember, minimum planing speed is a function of speed/length/weight. It has nothing to do with engine RPM. A fin of sorts may help you plane by lifting the stern at lower speeds. Also try relocating the center of gravity,,,move some things forward.
posted 04-16-2001 06:49 PM ET (US)
I put a Doel fin on the Merc 50 2strk mount on a Montauk. Before the fin, trim had almost no effect and I wasn't sure it was up on plane fully.
After the fin, big difference. Trim has more of an effect and 3/4 throttle (20 mph) planing is easy even with a full load.
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