boat handling twin i/o's

[handball]

Is there anyone with experiance that can tell me something about docking a twin i/o boat?I have been told that this setup will not pivot the way a boat with twin inboards can.In my marina we usually have to dock in a cross wind and back between pilings.The boat size would be say 28 to 30 feet and have {2} 260 h.p.engines.I have extensive experiance with inboards but none with i/o's.<br />Also if given proper maintenance can i/o's be reliable on long cruises?

 

[Mumblerone]

Re: boat handling twin i/o's

Handball...I look foeward to the answers you get. I have twin outboards, I can't see why it would be different. The thing I believe you'll see different Vs inboards is that the turning point is located at the motors Vs amidship. You are also directing the thrust Vs turning a rudder. Will take a little getting used to, but should present no problems. The only difference I can 'see' is that you can see the outboards Vs the I/O's.

 

[Norm Malcosky]

Re: boat handling twin i/o's

Handball-<br />I have a 32' Chris Craft with twin Volvo Penta SX stern drives. It is very easy to handle, but as Mumblerone says, the boat pivots about the stern drives when one engine is forward and the other in reverse.<br /><br />Backing should not be an issue as the prop's thrust force can be directed (turned)- in contrast to an IB that can only deflect water flow with the rudder. <br /><br />As far as maintenance, the I/O should last as long as your car's transmission if you keep water out of the oil and avoid hitting your prop or running gear on the bottom. <br /><br />My earlier Volvo 280 drives have lasted twenty years without any problems. Change oil annually, replace bellows every five years, and look for water in the oil when it is drained. <br /><br />I also use magnesium anodes on my drives since I boat exclusively in fresh water. This keeps corrosion pretty well in check. Not sure about salt water -but be aware that the Mercruiser III drives are suspected corrode-ers.

 

[Capt Ken]

Re: boat handling twin i/o's

One of the major problems is most twin sterndrives aren't counter-rotating drives. Those that are, fair a little better at docking due to the "walking effect of the prop". Usually inboards swing a bigger prop than sterndrives and thus a better bite on the water thus better walking effect. You can do the same with a sterndrive but you must not be afraid to get on the throttle. That's where most people get into trouble is by not using enough power to make the boat perform like they want it to. Back in the oil fields, I could take a 120 ft crewboat and walk it sideways down a seawall, but it took full throttle with one of the four engines in reverse and the other in forward. Get out in the open water and practice around some bouys. See how proper management of the throttle can produce better results.

 

[handball]

Re: boat handling twin i/o's

capt ken,<br />Thanks so much for your input on handling,one thing I did not know was the fact that outdrives turn the same direction.Doesn't that cause the boat on plane to turn to the right if both engines rotating in the same directions? If so how much pressure is needed to keep the boat straight and on course?<br />In the past when docking a twin screw inboard most of the time I center the wheel and forget it, and leave the throttles just off of idle, while shifting to turn the boat as needed. <br />Do outdrives require turning the wheel as well as reving throttles to back into a slip in a crosswind? Also do the props tend to walk the stern to port as in most inboards?<br />Been away from power for a while and wondering if outdrives would be ok for cruising. <br />Handball

 

[Boatist]

Re: boat handling twin i/o's

Handball<br />If you do not have counter rotating prop and just standard prop then yes the stern will kick to port in foward and to starboard in reverse. I think you will find I/0 easier to get into your slip. You can still split your engines but also when turn engine thrust turns and is more effective than just stearing with a rudder.

 

[Capt Ken]

Re: boat handling twin i/o's

Just the opposite. Outdrive turn clockwise when not counter-rotating. Forward makes them want to pull starboard and reverse pulls to the port. When you turn the outdrive in reverse, you start the bow to swinging opposite the direction you are wanting to go. Putting a boat with sterndrives in a slip is alot harder than an inboard. Its like dancing with a different woman. The music is the same, but they just don't move the same way.

 

[handball]

Re: boat handling twin i/o's

Capt ken:<br />sounds like the i/o's turn the same way the standard inboard engine , that means the stern walks to port in reverse. dont have any experiance with i/o's but there is nothing like docking a twin screw inboard . Its a great feeling to be able to walk that baby anyplace you want , and to pivot it around in its own length.<br />Right now I am actively looking for a sea ray about 1988 with inboards and prop pockets.I hope to find one by spring time.So far the main problem I have found with the 30 weekender is hatch and window leaks. Ihave time yet as I have a 1985 32 foot ericson sailboat that I need to sell before buying the sea ray. anyone know of other problems to look for in the 30?