How to launch stern drive safely?

Serf27

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Aug 23, 2018
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Hey everyone. I’ve been working on my OMC V6 Sterndrive for about 5 years. Each year it’s the same story, “I’ll take it out this time”
Now I’m finally ready.
New water impeller
Al sorts of new gaskets, new wiring and new throttle cables.
Couple loose ends left.
Spark plugs, can’t remember if I changed those, new oil and new water temp sensor/gauge.

Back to the question, how do I properly and safely launch the boat in shallow water?
I remember reading in the past to NOT apply any throttle until the drive in all the way down and the gears are properly mated. Doing this would press the gears out of place?

I ask because I see my father in law launch his boat and he has the drive semi down to get out of shallow water until the boat is deep enough to fully lower the drive/prop.

So how do you do it?

Thanks.
 

Scott Danforth

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OMC made many drives. specifically what drive do you have?

how shallow is shallow. 3 feet, 1 foot, 10 feet

guessing by your comment on the drive all the way down, you have a stringer

in that case, never above idle, and the drive down partly (remember, you are eating up the ball gears at this point). and as soon as you are in 3 feet of water, drive all the way down (you will hear the drive go wrrrrrrrrllllll-CLUNK, as soon as you are in 5 feet of water, hit the trottle to get on plane.

if you have a 3.0 liter and a stringer 400, you will need to be trimmed all the way down at the start of the hole-shot. as the boat climbs the hole, keep trimming up until the boat starts to porpoise. then tap the trim button down twice
 

Lou C

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Yes if it’s a stringer you must do as Scott says but if you have a Cobra (uses a gimble & trim system just like a Mercruiser), you back in till the stern is floating put the drive down about half way and then you can back off the trailer. With the drive half way down you can run in about 2.3-3 feet of water. Just keep it at idle speed to go easy on the ujoints.
 

Serf27

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Thank you both.
It is a stringer.
I’m not sure how shallow. Like unloading the boat or loading or pulling up close to land on the side of the lake.

So never leave the drive at the half point above idle?

At idle, with my gear selector in idle, the prop won’t spin. So would I just touch the lever to the reverse gear and let it slowly pull me back into the water?

The drive noise “wrlllllll-clunk” will be a normal noise that happens?

Thanks for the trim tip.
I think it’s a 3.5.
On that note, trimmed all the way down when the entire motor is sitting flat, raise trim until the front of the boat starts bouncing up and then drop the trim with 2 clicks of the button?
 

kenny nunez

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Just as SD said it is safe to idle in forward or reverse gear with the drive raised enough so as not to grind up the propeller or break a gear. Just be sure to put it down when you are clear of the shallows.
 

southkogs

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Your drive tilts from one switch, and trims from another. Shallow water, you can idle in gear (like Scott says) and then lower the drive as soon as you can. After that you trim with the other switch.
 

Scott Danforth

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the "wirrrrrlllll-CLUNK" is the sound the drive makes when you lower it. you hear the whirl of the gear motor, and when the drive hits home, its a loud "CLUNK"
 

Redrig

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Do yourself a favor as well. When you do get to that deeper water , don't hold the switch down.... don't slam it into the down position. Tap it down in bursts.

The tilt motor is a royal pita to change and if you slam it down , you will break something eventually
 

southkogs

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the "wirrrrrlllll-CLUNK" is the sound the drive makes when you lower it. you hear the whirl of the gear motor, and when the drive hits home, its a loud "CLUNK"
I think you should record an audio of what it should sound like and post it. I want to hear how accurate your sound effects are 😁
 

Scott Danforth

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I think you should record an audio of what it should sound like and post it. I want to hear how accurate your sound effects are 😁
you owned one. you know the sound. you probably know the sound of the worn ball gears too
 

Serf27

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Thanks everyone.

I changed the tilt motor about 2 years ago.
It’s only seen land use since then.

I was able to start the boat up today.
I think I understand this gear in idle that has been mentioned.

Is that when the gear lever moves into/drive/reverse and the prop starts to spin?
Probably play it safe And move the lever to the center position to stop the ball gears from spinning and then lowering the drive?

Here’s how my gear lever/propeller works.
When it is pointing straight up, with the engine on/idle, the prop does not spin.
If I move the lever forward or back about 1”, the prop starts spinning whatever way the lever is moved.
If I continue to move the lever forward/backwards, I can hear the engine Rpm’s start to climb and the prop starts moving faster.
Does all this sound correct?

Should the prop have that position in which it doesn’t spin when the lever is straight up with engine on?
 

kenny nunez

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The ball gears are always turning when the engine is running.
Yes, the propeller does not spin in neutral. Your throttle /shift is working as it was designed.
 

Serf27

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Ok great that it’s working as it should.
So to to the take off in shallow water.

I move the throttle to the idle position in which the propeller first begins to spin pretty slowly and keep the throttle in that position until I can drop the drive all the way and take off?

I have not looked at the propeller while the throttle makes prop spin in idle.
In the 2” range of motion before engine rpm increase, does the propeller spin at the same speed? Or will it spin faster if I move the throttle around in that idle position?

Thanks.
 

southkogs

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While everything said here is accurate, and you want to pay attention to it: don't over-think it.
  • Lower the drive as far as you safely can for the water conditions.
  • Start the engine. - Idle should be in the neighborhood of 800 RPM (If I recall correctly).
  • Throttle up for your gear to engage and the boat begins to make way.
  • Move at no-wake speed to deeper water.
  • Bump the tilt button until you hear the drive "clunk" in the down position.
  • Throttle up as desired, trim as needed (if available) and enjoy.
The whole deal is taking care of those ball gears while the drive is not fully down. Occasionally, you may have to break the rule and give the drive a little extra power (due to wind, waves, whatever). The ball gears should make a nasty-metal-grinding-ish sound because they're grinding metal off each other. You want to do that as little as possible.
 

Serf27

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Yea I am over thinking it.
The ball gears don’t look easy to replace and I’m trying to avoid that.

I don’t think I’ll be in this position much with drive half way, but thank you for all the info.
 
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