different question on motor height

lingcod

Petty Officer 2nd Class
Joined
Jul 27, 2004
Messages
181
I have been searching and the one thing that I cannot find is, what trim position do you have the motor in to determine cav plate to keel distance. do you trim it all the way in? if so, do you measure the height based on the aft portion of the cav plate? Do you level the motor so the cav plate is in line with the keel?

lingcod
 

scoutabout

Lieutenant Commander
Joined
Oct 14, 2006
Messages
1,568
Re: different question on motor height

The factory-mounted motor on my boat has the anti-ventilation plate (probably what you are referring to) level and even with the bottom of the keel. In this position the trim is bumped up ever so slightly.

enginerigging2.jpg


In order to achieve this relationship between engine and hull, you can see that the engine is actually raised off the top of the transom about an inch. Never been real happy with the look of this as it must mean a huge load on those thru hull fasteners during sharp turns under heavy acceleration.

Not to mention those hooks on the engine mount aren't being used to transfer fore and aft load to the transom, either. I'm assuming, however, they knew best when it came to rigging the boat. Good enough for 90 hp I guess...Not sure I'd want to see this with 225...:redface:

enginerigging1.jpg
 

lingcod

Petty Officer 2nd Class
Joined
Jul 27, 2004
Messages
181
Re: different question on motor height

The factory-mounted motor on my boat has the anti-ventilation plate (probably what you are referring to) level and even with the bottom of the keel. In this position the trim is bumped up ever so slightly.

enginerigging2.jpg


In order to achieve this relationship between engine and hull, you can see that the engine is actually raised off the top of the transom about an inch. Never been real happy with the look of this as it must mean a huge load on those thru hull fasteners during sharp turns under heavy acceleration.

Not to mention those hooks on the engine mount aren't being used to transfer fore and aft load to the transom, either. I'm assuming, however, they knew best when it came to rigging the boat. Good enough for 90 hp I guess...Not sure I'd want to see this with 225...:redface:

enginerigging1.jpg
Thank you for the advice but that is not really what I was asking. I wanted to know the position of the motor as far as trimmed in, trimmed out or nuetral when measuring the height of the cav plate in relation to the keel. BHILE says level with the keel surface, as in running a straight line down the keel from bow to stern and keeping that line, line up the cav plate. do you agree?

lingcod
 

lingcod

Petty Officer 2nd Class
Joined
Jul 27, 2004
Messages
181
Re: different question on motor height

nice pics though, interesting that my 150 yamaha has the same gap and is also installed in the 2nd hole from the top. puts my cav plate 1/2" above the keel.

lingcod
 

1979checkmate

Petty Officer 1st Class
Joined
Jan 15, 2011
Messages
261
Re: different question on motor height

propshaft should be parrallel with the bottom of the boat. Also ^^scoutabout^^ get a jackplate put on that thing! you will be amazed at the difference in performance and most of all handling just but setting the motor back another 4-6 inches.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,109
Re: different question on motor height

Scout, There are no transom clamps on modern outboards. They are held on by four 1/2" thick Stainless Steel bolts, which is much more secure than it needs to be. I would espect the transom bracket to break before the bolts do.
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
Re: different question on motor height

What bhile said, level the motor. From your photo, looks like you're set up about right. On a boat like yours and mine it's not that critical and is really a happy compromise, but for performance/bass/flats boats where speed or shallow running is important folks install jack plates to adjust motor height. Good Luck!
 
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