Hard turn with twins

dsiekman

Senior Chief Petty Officer
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Jul 7, 2010
Messages
798
Okay, so I'm still learning how to handle the twins. If I am trimmed up and cruising - say 3000 rpms and 30 knts - and turn the wheel hard over, the outside drive sounds like its starting to cavitate. Should I trim down if I'm planning this maneuver? I've also tried dropping speed on the inner engine and speeding up the outer, but it doesn't seem to do much. I love the way the boat handles, just looking for some "advanced" driving tips. Thanks
 

EddiePetty

Lieutenant Junior Grade
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Aug 25, 2008
Messages
1,008
Re: Hard turn with twins

We don't own twins but common sense tells me that the 'outside' engine will be pulled out of the water in a high speed turn thus reducing the prop 'bite' and probably ventilating. Either reduce speed or trim the boat for a hard turn to maintain prop depth.
 

reddogg

Petty Officer 1st Class
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Jun 3, 2011
Messages
379
Re: Hard turn with twins

X2, either reduce speed, reduce turn radius, or trim down a bit.

Red
 

EddiePetty

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Re: Hard turn with twins

"..... reduce turn radius...."

Don't ya' really mean INCREASE turn radius???
 

reddogg

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Jun 3, 2011
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379
Re: Hard turn with twins

lol, duh, yeah, thats what I meant:)

Red
 

dsiekman

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Jul 7, 2010
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798
Re: Hard turn with twins

Thanks, guys. That was my guess, just wanted to see if there was anything I was missing.
 

smokeonthewater

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Re: Hard turn with twins

with twins you have more levers and as we all know when dealing with half pin barrel hinges, with the proper application of leverage the door will pop free..... lol


anyhow I too am still getting used to my twins.... So far everything at speed is the same as any other boat.... I HAVE tried just trimming the outside engine down for a turn and while it seems to work, I prefer to just trim both down.... My boat handles like a go cart at speed. Really surprised me for the size.....

The REAL fun with twin i/o's is docking.... Especially in a crosswind or current.... If you engage only one engine and turn the wheel to that side enough to go straight you will side slip to the opposite side... putting the second engine in reverse and turning further toward the side of the engine in forward while slightly increasing throttle on the forward engine will increase the side slippage..... Takes some practice but can be very helpful

BTW Use those directions for a starting point but don't dwell on em too long..... I'm getting pretty decent at DOING it but I'm not sure I'm worth anything at DESCRIBING it LOL
 

Capt'n Chris

Chief Petty Officer
Joined
May 21, 2009
Messages
461
Re: Hard turn with twins

Shift the inside motor into a hard reverse...that'll spin ya! And cost ya! Will be quick tho.
 

dsiekman

Senior Chief Petty Officer
Joined
Jul 7, 2010
Messages
798
Re: Hard turn with twins

with twins you have more levers and as we all know when dealing with half pin barrel hinges, with the proper application of leverage the door will pop free..... lol


anyhow I too am still getting used to my twins.... So far everything at speed is the same as any other boat.... I HAVE tried just trimming the outside engine down for a turn and while it seems to work, I prefer to just trim both down.... My boat handles like a go cart at speed. Really surprised me for the size.....

The REAL fun with twin i/o's is docking.... Especially in a crosswind or current.... If you engage only one engine and turn the wheel to that side enough to go straight you will side slip to the opposite side... putting the second engine in reverse and turning further toward the side of the engine in forward while slightly increasing throttle on the forward engine will increase the side slippage..... Takes some practice but can be very helpful

BTW Use those directions for a starting point but don't dwell on em too long..... I'm getting pretty decent at DOING it but I'm not sure I'm worth anything at DESCRIBING it LOL

Okay, not sure I understand that maneuver, but I'm willing to give it a shot. One note, I'm running counter-rotating props which limits prop walk. Not sure if this move will work for me or not.
 

dsiekman

Senior Chief Petty Officer
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Messages
798
Re: Hard turn with twins

Shift the inside motor into a hard reverse...that'll spin ya! And cost ya! Will be quick tho.

Just rebuilt both drives this winter due to seal failures. Not interested in doing it again. My bank account isn't interested either.
 

rbh

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Re: Hard turn with twins

I think I would have to have my rub rail touching the water before my outside drive came out of the water enough to cavitate.
 

dsiekman

Senior Chief Petty Officer
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Messages
798
Re: Hard turn with twins

I think I would have to have my rub rail touching the water before my outside drive came out of the water enough to cavitate.

Okay, perhaps it isn't cavitating, but it definitely sounds/feels different. I have watched the tach and will pick up maybe 1-200 rpms on the outer engine if I really through it over. We checked the gimbles and u-joints this spring, so that isn't it either. As for the rub rail being in the water, she's leaned over pretty good but probably not quite that far.
 

rbh

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Re: Hard turn with twins

But as you said your all trimmed out and there is a big difference between 24 inches of water the props pushing straight and say 6 inches on angle, yup, as was said trim in alittle.


(You've been getting a blow out :D)
 

Mischief Managed

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Re: Hard turn with twins

Okay, perhaps it isn't cavitating, but it definitely sounds/feels different. I have watched the tach and will pick up maybe 1-200 rpms on the outer engine if I really through it over. We checked the gimbles and u-joints this spring, so that isn't it either. As for the rub rail being in the water, she's leaned over pretty good but probably not quite that far.

The outside prop is taking a longer path than the inside, that may account for the increase in RPM. Is there a proportional decrease on the inside prop?
 

smokeonthewater

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Re: Hard turn with twins

Okay, not sure I understand that maneuver, but I'm willing to give it a shot. One note, I'm running counter-rotating props which limits prop walk. Not sure if this move will work for me or not.

imagine it this way.... if you push forward on the left side of the rear ONLY it will cause the front to turn slightly toward the right.... you then must steer the rear toward the right(EDIT: which means turning the wheel left) to keep from turning to the right.... now you are pushing diagonally to the right and moving diagonally to the right.... now you shift the right engine into reverse and suddenly you are pivoting to the right so you steer further to the left and slightly increase throttle on the left (forward) engine to push the rear even more to the right
CR props will not have any effect on this

BTW the prop on your outboard engine is NOT cavitating, it is ventilating... It also has nothing at all to do with traveling in a greater ark.... You are all trimmed out for max speed.... If you trim up just a little more what happens? That side increases RPM because it is too close to the surface and is sucking in air.... Now start a turn... one side of the boat goes lower and one goes higher.... now the outboard drive is too high just as if you had trimmed up further.....
 

dsiekman

Senior Chief Petty Officer
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Jul 7, 2010
Messages
798
Re: Hard turn with twins

That's some pretty fancy footwork! I'm going to give it a shot this weekend!
 

smokeonthewater

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Re: Hard turn with twins

it isn't an exact science and the further apart your engines (drives) are the better it will work

practice where you have plenty of room and no expensive boats to hit....
 

JoLin

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Aug 18, 2007
Messages
5,146
Re: Hard turn with twins

it isn't an exact science and the further apart your engines (drives) are the better it will work

practice where you have plenty of room and no expensive boats to hit....

I'm also new to twins and was having a tough time manipulating control levers and steering to get the boat to go where I needed it to during docking maneuvers. A friend who's been running twins forever told me in no uncertain terms to 'keep your hands off the steering wheel!'

Now I center the wheel and use only the shift/throttle controls to push, pull and prop steer me. Works MUCH better.

My .02
 

smokeonthewater

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Re: Hard turn with twins

I do that with twin inboards except when I want to slide sideways... I still like the steering wheel on the i/o's most of the time.... I do often turn the wheel away from the dock I'm gonna tie to and then use only the shifters from that point..... I'm stubborn tho and honestly the more difficult something is the more I enjoy making it look easy :D
 
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