Query about raising outboard 6" on transom

[iamspartacus]

Hi folks, I need to check the viability of raising my outboard about 6" higher (By simply removing and remounting from top to bottom bolts on transom bracket)
I want to do this so I can get the trim rams out of the water as this boat is on a mooring all of the time.

Hopefully there is enough in the picture attached. What should I be considering when raising the motor up a bit. You can see the resting waterline where the colour changes (antifoul)
The water intake will be still well underwater, is there anything else I should think about ?

I assume it's just fours nuts, pull it off and raise it and nuts back on again. Unless you think I need a plate in between ?

 

[Scott Danforth]

buy a jack plate. that way you can raise it for mooring and then lower it to use it.

if you raised the motor 6", you would never get on plane, and even though the pickup ports are below the water, the water pump wouldnt be and it would never prime and you would toast your impeller the first time you ran it.

 

[gm280]

WOW, that is a lot of raising. If you don't set it back from the transom, like Scott stated above, you will burn up the engine in short order just raising it 6". But when you set the engine back from the transom (via a jack-plate), the water gets angled into the water ports. Usually the set back should be equal to the raise in height. But whatever you do, make absolutely certain your water pump is working properly when on a plane. It is that important...

 

[Sea Rider]

Simply tilt the motor fully up, the lower leg should not be in contact with the water level...

Happy Boating​

 

[iamspartacus]

Simply tilt the motor fully up, the lower leg should not be in contact with the water level...

Happy Boating​

It's the trim rams I need to raise

 

[iamspartacus]

buy a jack plate. that way you can raise it for mooring and then lower it to use it.

if you raised the motor 6", you would never get on plane, and even though the pickup ports are below the water, the water pump wouldn't be and it would never prime and you would toast your impeller the first time you ran it.

Thanks for the reply. Hydraulic jack plates might be 50% of the cost motor so I don't think I'll go down that path. I think I have found some good information on where it really should be placed and maybe I can get 2-3" out of it. That would be enough as I just need to raise it just a tiny bit.

 

[Scott Danforth]

as you raise the motor and the anti-vent plate comes above the bottom of the hull, you will eventually ventilate as you apply throttle. from what I see, your motor height is perfect.

 

[racerone]

Just raise the motor 5"-----Then install a 5" extension kit to put the lower unit in the right place.-----

 

[iamspartacus]

as you raise the motor and the anti-vent plate comes above the bottom of the hull, you will eventually ventilate as you apply throttle. from what I see, your motor height is perfect.

ok, maybe i'll have to wait for next boat to solve this problem then, cheers

 

[racerone]

Search for ----bay manufacturing-----They offer a complete range of extension kits.

 

[Scott Danforth]

not sure what the issue is with the cylinder sitting in the water. not ideal, however thats common.

how old is the boat?

if you have water soaked foam you could be sitting 2-3" lower in the water than you would if the hull was dry.

when was the last time the boat was weighed?

 

[Sea Rider]

Not sure what the issue is with the cylinder sitting in the water. not ideal, however thats common.

​

Yep it's quite common seeing such scenario on heavy boats powered by heavy motors moored for long terms on water, worse if floating on salt water.

Happy Boating

 

[Sea Rider]

This scenario says it all, owner now prefers not to moor the combo but rather take it out of water when returning to terra firme as he doesn't know when will be using the combo again. BTW the lower SB has been scrapped/brushed clean, shows paint deterioration, pitting.

Happy Boating​

 

[iamspartacus]

not sure what the issue is with the cylinder sitting in the water. not ideal, however thats common.

how old is the boat?

if you have water soaked foam you could be sitting 2-3" lower in the water than you would if the hull was dry.

when was the last time the boat was weighed?

This main problem I have is that the aluminum endcaps get eaten away at the edges and if I leave it too long (a few years) it will eat right through and water can get in.
I'm not sure if it is electrolysis generated by the leg bouncing in and out of the water. My anodes are fine and I cannot quite work out exactly what the core cause is. Hence my desire to raise it just a few " and then it will be out of the water alltogether.

I've also tried various primers and two pack acrylic protection on the ends caps and so far regular nail polish seems to provide the best protection actually, it sticks better and doesn't seem to cake away after 9 months or so in the water,

I've never weighted the boat, but am thinking of adding some water ballast bags in the bow to add some weight up front, which also helps a lot in choppy waters.

 

[iamspartacus]

not sure what the issue is with the cylinder sitting in the water. not ideal, however thats common.

how old is the boat?

if you have water soaked foam you could be sitting 2-3" lower in the water than you would if the hull was dry.

when was the last time the boat was weighed?

Boat is a ~ 1988 build and engine is a 2004 model. I've had it moored in salt water since 2015. I've resigned myself to replacing the endcaps each year - that's the only real issue I have.

 

[Chris1956]

The aluminum of the PTT unit should not get eaten away when moored in saltwater. You should have a zinc anode on the motor, usually under the PTT unit. You are not using copper-based antifouling paint on the motor, right? If that blue paint on the gearcase is copper based, it will eat away your motor PDQ.

 

[iamspartacus]

The aluminum of the PTT unit should not get eaten away when moored in saltwater. You should have a zinc anode on the motor, usually under the PTT unit. You are not using copper-based antifouling paint on the motor, right? If that blue paint on the gearcase is copper based, it will eat away your motor PDQ.

Using Trilux33 and yes there is an anode right below.

 

[Chris1956]

Using Trilux33 and yes there is an anode right below.

OK, The zinc anode is clean and bare? You could add more anodes. There are ones that screw onto transom bolts, and other universal ones as well.

Alternatively, maybe there is stray current in the water? Do you moor in a marina with boats with shore power? Do you have shore power? Leakage from shore power can cause serious galvanic corrosion.

 

[Scott Danforth]

send the next aluminum end caps out for hard anodizing. then paint over them.

 

[iamspartacus]

send the next aluminum end caps out for hard anodizing. then paint over them.

Interesting idea that's a bit more robust than my nail polish and acrylic epoxy
Would need to take out any rubber components (o rings etc) I assume.