I have a Baby 16 with a Mercury 225HP 3.0L. The prop is a Mercury Tempest 27 P. When the boat pass 60MPH start to bounce side to side and are very inestable. I read this boat can run over 70. What I do wrong. Any help is apreciated.
David Vila
I have a Baby 16 with a Mercury 225HP 3.0L. The prop is a Mercury Tempest 27 P. When the boat pass 60MPH start to bounce side to side and are very inestable. I read this boat can run over 70. What I do wrong. Any help is apreciated.
David Vila
The largest motor available in the time these were built was around 135hp and the boats would run maybe 50's..............you are far exceeding the power and weight of what they were designed for. There are a few threads here that may help on this forum about getting them stable. Trim tabs can help and will a jack plate. Gearcase designs vary with some better than others.....lots of reading for you to do.
http://www.donzi.net/forums/showthread.php?t=54091
http://www.donzi.net/forums/showthread.php?t=61800
And post your hull number and year here.
http://www.donzi.net/forums/showthread.php?t=63670
Outboards also have the advantage of being easily raised up manually or jacked, it is more than worth while experimenting with the height above the transom. I have run several with the cavitation plate 2-3 inches above the bottom, that reduced or eliminated chine walk. Before you go out and spend $$$ try raising the engine up, most can be raised two bolt holes or more. The limiting factor is the water pickups, you can only go so high before you start having cooling issues.
Phil
No matter what your beliefs are "GOD BLESS AMERICA"
Fully retired marine tech near 60 years in the biz.
Are you using a single cable steering system? I had a 16' Tahiti with a 200 Mercury that would run high 70's low 80's depending on load and prop. Dual rack and pinion push/pull steering and solid motor mounts helped tremendously. I also found that using a exhaust over the blade prop such as a Mercury Chopper prop minimized the prop torque that can cause chine walk. And as MOP pointed out, raising the x dimension with a setback jack plate helps too. My prop shaft was 1" below the bottom of the boat with a 9" setback jack plate using a chopper prop. To use a thru hub exhaust prop, I had to lower the x dimension considerably.
http://compare.ebay.com/like/1705465...=263602_304692
Last edited by Barry Eller; 11-27-2010 at 06:22 AM. Reason: add photo
"YIPPY-KAI-YAY"
1993 Donzi Classic 22 by Chris Craft...
White with Yellow stripes...
502 King Cobra...
Its hard to be humble when you own a Donzi. (In my humble opinion).
To hear it run...click the link below...
http://s922.photobucket.com/albums/a...er_media_share
Exactly Carbo. It depends on the year he has, but safe to say an easy additional 80-100 lbs. Then based on what we uncovered in a previous thread on gas tank locations for a 1976, the tank could be back and viewable upon removal of the floor tub versus 12-14" further forward toward the bow. Then the last point is if the battery is mounted inside the locker in the rear lounge seat. I'm not convinced it can't be reworked with a decent result, but it all starts with if the transom lip is almost touching the water at rest. If the set-up can be properly re-worked, then the hamster motor options become MUCH MUCH more interesting for all 16 OB owners.
1972 16 OB - C16B-63 - "Surface Tension" Resto Project
1974 16 OB - DMR16106017-B - "The Mule"
I test the boat in FL. I live in PR and should receive the boat next week. The motor weight 451 lbs with cable steering. The steering is very tight. The boat is 100% original no mods. I see some 16 have 2.5 lt that weight 390 and a jack plkate 45lbs and hydraulic steering 12lbs a total of 447lbs. I beelive the problem could be the prop 27p. I choose the 3.0lt over the 2.5 for the torque. My goal is to achieve the fastest cruise speed at 4000 to 4500 rpm with 4 people. I need to top speed the boat to make the correct prop selector.
I thought you had a heavier Opti ................
1972 16 OB - C16B-63 - "Surface Tension" Resto Project
1974 16 OB - DMR16106017-B - "The Mule"
Single cable steering tight or not is not good, a set of solid mount like mentioned above and dual cable is the only safe way to go. Big outboards on small V hulls tend to get real wobbly, once they start to dance most the time it only gets worse. They react a whole lot different then a I/O boat, the weight is carried high only increasing the pendulum action IE: Chine Walk. Fooling with props can help some but getting it at the right height for the hull is key.
No matter what your beliefs are "GOD BLESS AMERICA"
Fully retired marine tech near 60 years in the biz.
Staring at he photo of the engine I would raise it two bolt holes for a start that will do more the any prop!
No matter what your beliefs are "GOD BLESS AMERICA"
Fully retired marine tech near 60 years in the biz.
I sure hope your transom is solid.... are you able to get insurance on that rig?
"YIPPY-KAI-YAY"
1993 Donzi Classic 22 by Chris Craft...
White with Yellow stripes...
502 King Cobra...
Its hard to be humble when you own a Donzi. (In my humble opinion).
To hear it run...click the link below...
http://s922.photobucket.com/albums/a...er_media_share
I will try to move up the engine first, make sense. Iff this dont work I can try another prop. A friend have an ET Ron Hill solid hub. Have a small diameter 12 3/4 but 30P. Finally change the steering system. I read the weight of the engine from the plaque have on it. The transom is solid. The boat never been repaired. I buy this boat from the second owner that have it for 27 years, 23 of it in a barn. This is my 2nd 16 outboard. The first one have a 200 V6 Mercury and ran close to 60mph. I hope get close to 60 mph cruising. Thanks for the input.
David Vilá
What year is the boat and what year is the motor?
1972 16 OB - C16B-63 - "Surface Tension" Resto Project
1974 16 OB - DMR16106017-B - "The Mule"
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