Engine Support Height

[Sea Rider]

Need to install a Tohatsu 18 HP short shaft next to a Mercury 225 HP engine to be used as a aux/kicker, have a alum engine bracket, the ones used for sailboats, has 5 position settings, the size of the boat is around 23 ft, would like to know :

1-Is it convenient to place aux next to main engine with sufficient space between them to rotate propely or better in center position of the available space leftover which has 22"

2-Are aux's installed left or right from main engine, or is it a personal decision ?

3-Will it be needed to mark sea level at transom's back when boat sits on water as a refference to position bracket properly ?

4-Is it possible to lock 18 and steer boat with main using it's tail as a rudder ?

Was thinking installing cav plate with at least 2" from keel and placing bracket in middle hole to rise or lower engine from that point. Will post some pics to have a clearer idea of the setup intention.

Happy Boating

 

[oops!]

Re: Engine Support Height

yep...post pics.

the anti cav plate must be at the keel line.
and its your choice...left or right

 

[Sea Rider]

Re: Engine Support Height

Hi experienced installers & boaters, need help on this one :

Was planning placing cav plate around 2" down from keel as seen at horizontal imaginary line as in pic 2, assume being such a big and heavy lump with an 18 horse as an aux will be mission impossible to plane, if so, wouldn't it be better to place cav plate to be 2" or bit more under waterline ? Probably will need to throttle sufficient to have a non planning horizontal lump boat at sea level as not to force needlessly the aux.

Would it be aceptable to place alum engine brackett to be in middle height setting after achieving above installation and be able to move cav plate higher or lower as needed for calm or choppy waters use. ? Must aux be positioned in middle portion of available space as seen on pic 3 or better slight towards main engine ?

Any tech installation advise is kindly appreciated.

Happy Boating

 

[smokeonthewater]

Re: Engine Support Height

really you have two concerns here..... I really don't think the bottom of the boat is as important as making sure the prop stays in the water in rough seas and that the powerhead stays out of the water in rough seas....... get the cav plate at or near the bottom of the boat and you'll likely be fine

 

[jacoboregon]

Re: Engine Support Height

The kicker does not need to be centered in the space. You should think ahead about possible wanting to install tabs in the future, and take that into account as you position the bracket.
You can tie the kicker to the main engine for steering.
You are correct about not planing with the kicker, so setting the height as you suggest should be fine. The kicker is generally used in case of main engine failure or for trolling. Planing and high speed travel is not the objective.

 

[smokeonthewater]

Re: Engine Support Height

Also when deciding where to mount the kicker, think about the tiller handle or routing the control cables

EDIT: with your ladder on the starboard the port is your only option

 

[smokeonthewater]

Re: Engine Support Height

I just caught that it was a short shaft..... Long shaft would be much better if you have a choice

 

[Sea Rider]

Re: Engine Support Height

I just caught that it was a short shaft..... Long shaft would be much better if you have a choice

We have already the short shaft kicker, if engine support has not been installed at this time + has 5 height settings, would placing a short or long shaft tiller engine make any difference at all ? you could always place bracket higher or lower to match your shaft's lenght, right ? The aux is to be used at emergencies only, owner is not very confient on his old 225 horse although has been completely overhauled. That's one of the issues of owning a real heavy lump compared to a much lighter boat you could tow more easily This week end will mark it's transom flotation line once on water and maybe start engineering from this point. Thanks for all imput so far....

Happy Boating

 

[JB]

Re: Engine Support Height

the anti cav plate must be at the keel line.
and its your choice...left or right

On many boats that would put it much too low. Put the anti-ventilation plate even with the boat bottom where the aux motor is mounted.

 

[Sea Rider]

Re: Engine Support Height

On many boats that would put it much too low. Put the anti-ventilation plate even with the boat bottom where the aux motor is mounted.

Thanks JB, was thinking same, aux cav plate at same height as main engine cav plate will be extremely too low, so to get your idea right, must place cav plate even(1) matching middle bottom hull's shape or slightly down (2) right ? Will try to match middle bracket setting to match that configuration in case you need to rise or lower a bit the engine for flat or choopy seas emergency uses.

Happy Boating