Seems like my outboard is not mounted correctly....Need advice please?

offthehook67

Seaman Apprentice
Joined
Apr 23, 2012
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46
Good morning,

I recently bought an 89' Alumacraft Dominator 16 tiller. It was repowered in 03' with an 01' Merc 50 4 stroke.

When throttling up with motor almost all the way down it gets right up and puts the bow down nice however, it sprays water to what I think is excessive like the motor is mounted wrong on the boat (Too Low). I looked at how it's mounted and everything seems correct. It is in the second hole down from the top of mounting plate and the motors anti-ventilation plate seems correct within one inch of the bottom of the hull. I have had other boats with trim n tilt and never experienced so much water spray before. It sprays on both sides like it's dragging in the water. When I trim it up it gets less and less of course but I have to trim it so far up that I lose power in order for it to stop dragging in the lake.

Is it possible that even though the motor is within the guidelines of a proper install that it is still to low on the transom?

Thanks and I look forward to all of your opinions and answers.

Antiventilation plate.jpg
 

greenbush future

Lieutenant Commander
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Aug 28, 2009
Messages
1,814
Re: Seems like my outboard is not mounted correctly....Need advice please?

My guess is you are trimmed to far in, this may drive the bow of the boat down once on plane, and create more of a large wake and some water spray from it. Maybe change your pin at the motor up one notch so the outboard isn't so snug against the transom. You might take a bit longer to plane out, but the boat should ride in more of a bow up mode?
 

offthehook67

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Apr 23, 2012
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46
Re: Seems like my outboard is not mounted correctly....Need advice please?

My guess is you are trimmed to far in, this may drive the bow of the boat down once on plane, and create more of a large wake and some water spray from it. Maybe change your pin at the motor up one notch so the outboard isn't so snug against the transom. You might take a bit longer to plane out, but the boat should ride in more of a bow up mode?

Well like any motor I start trimmed down for a better hole shot however, I begin to trim up as the bow comes down and begins to plane out. So I believe I am fine there but you bring up a good point in regards to the pin placement. Am thinking the pin placement is not an issue because this motor sprays something fierce until I have trimmed it up to a point where it's too far up and loses power. I finally reach a point trimming up where it stops spraying. It reminds me of a motor sitting too low on the transom and drags in the lake.
 

roscoe

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Oct 30, 2002
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21,754
Re: Seems like my outboard is not mounted correctly....Need advice please?

I think raising the motor an inch will take care of it.

If you can, take her out and get up on plane, then look to see if the anti ventilation plate is hitting the water at the front edge.
I bet it is.
 

Texasmark

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Dec 20, 2005
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14,780
Re: Seems like my outboard is not mounted correctly....Need advice please?

I think raising the motor an inch will take care of it.

If you can, take her out and get up on plane, then look to see if the anti ventilation plate is hitting the water at the front edge.
I bet it is.

+1. The purpose of that little horizontal plate sticking out front of the skeg about an inch above the AV plate is purposely to stop just what you mentioned. Apparently at times it is below the water level and that is the root cause of your problem. Jack her up.

Mark
 

offthehook67

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Apr 23, 2012
Messages
46
Re: Seems like my outboard is not mounted correctly....Need advice please?

Just a question: HAve you looked at it carefully and know that it's the outboard causing it and not something on the boat?

There is nothing else attached to the transom. No transducers or anything.

I am still leaning towards the motor needs to come up a notch.

I need to run to the lake and check to see if the front of the plate is in or out of the water on plane
 

saumon

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Aug 2, 2004
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Re: Seems like my outboard is not mounted correctly....Need advice please?

There is nothing else attached to the transom. No transducers or anything.

I am still leaning towards the motor needs to come up a notch.

I need to run to the lake and check to see if the front of the plate is in or out of the water on plane

Is the pic in your first post current? 'cause I see 2 transducers...
 

offthehook67

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Apr 23, 2012
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Re: Seems like my outboard is not mounted correctly....Need advice please?

Is the pic in your first post current? 'cause I see 2 transducers...

Yeah it's current. I installed those a couple days ago however, I have had the boat out a few times prior to installation of them and noticed the rooster tails port and starboard first time out. I have anti spray plugs in those transducers that work great at eliminating the spray from them. This question started after the first time I test drove the boat on the lake with nothing attached to the transom besides the motor.
 

saumon

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Re: Seems like my outboard is not mounted correctly....Need advice please?

Yeah it's current. I installed those a couple days ago however, I have had the boat out a few times prior to installation of them and noticed the rooster tails port and starboard first time out. I have anti spray plugs in those transducers that work great at eliminating the spray from them. This question started after the first time I test drove the boat on the lake with nothing attached to the transom besides the motor.

OK, so try raising your engine. That may cure the spraying...
 

offthehook67

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Apr 23, 2012
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Re: Seems like my outboard is not mounted correctly....Need advice please?

That was my conclusion as well. I just started this thread to justify my thoughts by hearing from others before I stated what I was thinking. My issue now is how the heck I am going to lift this engine by myself. I don't have a hoist or pulley so I'm pondering alternatives.

Thanks everyone and happy boating
FYI the lakes in the northern half of Minnesota (my home state) are still loaded with thick ice and our MN fishing opener is this Saturday. I am choosing to stay home and figure out this motor height.

Keep on keepin on!!!!
 

saumon

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Re: Seems like my outboard is not mounted correctly....Need advice please?

I've done it a few times with a 90hp (when changing props you sometimes need to play with height). Lower the trailer tongue as low as you can. Then, place a piece of wood (I use a scrap piece of 2"x6") under the skeg and trim it down until it's firmly set against the wood. Remove the top 2 bolts from the holes and loosen the lower 2 in the slots. Slowly raise your trailer jack (this will lower the transom) until the next holes up match.

The holes being spaced 3/4" apart, I'd start with 2 holes up (1.5") if it's spraying that bad.
 

blackhawk180

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Jun 14, 2012
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Re: Seems like my outboard is not mounted correctly....Need advice please?

I've done it a few times with a 90hp (when changing props you sometimes need to play with height). Lower the trailer tongue as low as you can. Then, place a piece of wood (I use a scrap piece of 2"x6") under the skeg and trim it down until it's firmly set against the wood. Remove the top 2 bolts from the holes and loosen the lower 2 in the slots. Slowly raise your trailer jack (this will lower the transom) until the next holes up match.

The holes being spaced 3/4" apart, I'd start with 2 holes up (1.5") if it's spraying that bad.

Well, I learn something every day. That's a brilliant plan to raise the motor saumon! I had the same problem as offthehook67 and hauled my boat up to a buddies shop with a chain hoist. Same results but with considerable more hassle than your idea (OK, we did get to drink a few more beers with the chain hoist plan). BTW, it drastically reduced spray and improved top speed a bit. Let us know how it works out for you, offthehook67.
 

jestor68

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Jun 12, 2012
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Re: Seems like my outboard is not mounted correctly....Need advice please?

I've done it a few times with a 90hp (when changing props you sometimes need to play with height). Lower the trailer tongue as low as you can. Then, place a piece of wood (I use a scrap piece of 2"x6") under the skeg and trim it down until it's firmly set against the wood. Remove the top 2 bolts from the holes and loosen the lower 2 in the slots. Slowly raise your trailer jack (this will lower the transom) until the next holes up match.

The holes being spaced 3/4" apart, I'd start with 2 holes up (1.5") if it's spraying that bad.
You left out the second person to crank the crank because you will need to be back there holding the motor. There is a u tube video of a couple guys doing it.
 

roscoe

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Oct 30, 2002
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21,754
Re: Seems like my outboard is not mounted correctly....Need advice please?

And if your motor does not have the slotted mounting holes, you need 2 guys to balance the motor, and one to crank the tongue jack, while you fiddle with the bolts and talk on the cell phone. :)


I have swapped engines many times, up to 125 hp, with a pulley on the garage rafter, and the winch on my atv.
 

saumon

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Re: Seems like my outboard is not mounted correctly....Need advice please?

With the slotted lower holes and the bolts barely loosened but still there, I've done it alone a few times without problems.
 

etracer68

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Oct 11, 2009
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906
Re: Seems like my outboard is not mounted correctly....Need advice please?

From what I see in the pic, your AV plate is about 1/2" below the bottom of the boat. I would do as suggested, and bring the motor up 1 1/2". Most are setup 1" above to start. Alot of good info, on how to raise the motor, with keeping the bolts in the slot, but loose. Keep us posted on results.
 

offthehook67

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Apr 23, 2012
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Re: Seems like my outboard is not mounted correctly....Need advice please?

Wowzers!!!!

Thanks for all the good info guys....Looks like this thread helped more than just me :) Always a good thing.

I like the idea about lowering the tongue however I will not be able to do it myself as mine does not have lower slots it has holes. My first thought is to take it back to the lake (5 min from my house) Lucky and get it on plane and then try not to fall in the lake while steering at full speed and getting a good look over the transom and eyeball where the anti - ventilation plate is actually running. If it is what we are all thinking and dragging below the water surface then yup it's got to me hoisted up. I am going to try and determine how low it is in the water on plane to determine whether I should go one hole up or two.

To add to Saumons idea with a DYI lift I was thinking about adding a 2" ratchet strap around the head of the motor and connect it to the rafter in my garage to help balance it and allow me to move the motor into place while I fight the bolts lining up wheil on cell phone drinking beer and smoking cigs while ignoring girl friend bugging me at the wrong time while I am slamming my fingers between the motor and transom.....Lord that actually sounds like real life....haha

I will let you all know how it goes. I cannot get to it until early next week but I will be on it like white on rice!!!!

Later guys and have a great weekend!
 

smokeonthewater

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Dec 3, 2009
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9,838
Re: Seems like my outboard is not mounted correctly....Need advice please?

a floor jack under the skeg (preferably in grass so it won't easily roll) and a helper makes short work of this job... Best if the trailer is hooked to your truck so the boat can't roll away from the motor....

Be VERY cautious trying to hoist or even balance with a strap.... Unless you are using a hook to the center of the flywheel, an outboard can be VERY top heavy and things can go bad FAST.
 
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