Brand New Boat and Motor and won't plane out.

[eyes4u]

I have a friend who called me from a far north fishing trip with a problem with his brand New Lund 1750 Tyee. He said that no matter how much throttle he gives it, and no matter for how long he holds it , he can not get it to plane out without moving the two passengers to the bow. Here is the equipment:

1750 Tyee
115 Merc Optimax
9.9 Pro-kicker
1/2 tank gas


I did notice in the pictures that he sent me that the top of the cavitation plate when the engine is trimmed all the way down is 4 to 5 inches above the bottom of the keel. This seems to be too high, as far as I am concerned. Additionally, the 'seat' on the engine bracket looks to be about 2-2.5" above the top of the transom.

I did verify that the engine was trimmed down all the way. Can someone help me confirm that the engine is mounted too high on the boat?

 

[jigngrub]

Re: Brand New Boat and Motor and won't plane out.

Here's your confirmation.

http://www.marinepartsman.com/installing-an-outboard-on-your-boat.html

Cav plate should be flush with the bottom.

 

[H20Rat]

Re: Brand New Boat and Motor and won't plane out.

I did notice in the pictures that he sent me that the top of the cavitation plate when the engine is trimmed all the way down is 4 to 5 inches above the bottom of the keel.

Don't need to read any more, your problem is right there! On most boats, you start out with the anti-ventilation plate (technically not a cavitation plate) even with the bottom of the keel, and then adjust from there. 4-5 inches is WAY too high for that type of boat.

 

[Texasmark]

Re: Brand New Boat and Motor and won't plane out.

Here's your confirmation.

http://www.marinepartsman.com/installing-an-outboard-on-your-boat.html

Cav plate should be flush with the bottom.

That pic is right out of my Merc Service manual as part the installation diagram/paragraph, course I don't know what's the chicken and what's the egg.....who developed it and who copied it...but it does look like a Merc.

So just how do you wind up 3-4 inches off.....SWAG says that someone put a 15" engine on a 20" transom, or a 20 on a 25 or vise versa....I mean, OB boats/motors conform to a set of dimensions and when you are that far off, someone mis-installed some equipment.

On just where the "anti-cavitation" plate for 40 years, corrected by IBoats xperts to an "Anti-vent" plate, which it surely is, is supposed to be with respect to other things (bottom of boat, water under the transom while at WOT kind of things), there is a lot of debate about that.

Based upon all the xperts who comment on this site regularly (self included....Ha!), and my 50+ years of boating experience, there is no set number......like everything else it depends on your equipment and your situation (usage, kind of environment you boat in).....but we are talking about 1 or 2 inches, not the numbers discussed in this thread. Unless you are an offshore racer and using cleaver props and all that high performance equipment. Grin.

I'm not going to tell someone where to put theirs. I will tell them what I have, what I do with it, where it sits and what it does for me, and why I did what I did. If I were a marine mechanic or dealer who has had unlimited experience with different equipment/installations and situations, then I would feel qualified to advise.
I might question something they may say as to whether or not it makes good sense to me and why I feel that way.....

When I have a new piece of equipment, I move things around/change things till I get the best of what I am after. For a lot of folks, that may be more than they want to do, but it's free advice and they are free to take it or leave it.

I hope my jibberish did someone some good. I'm retired. The lady in my life said that I needed a hobby so I got back on Iboats. Keeps my typing skills tuned and my mind active. I don't get out as much as I used to, but when I do I have 2 speeds.....N and F at WOT. Grin.

Mark

 

[Home Cookin']

Re: Brand New Boat and Motor and won't plane out.

the two parts that struck me are "brand new" and "far north." The dealer owes him a new (different) motor. The logistics are not encouraging.

 

[roscoe]

Re: Brand New Boat and Motor and won't plane out.

I've seen several new boats this year, that have an extraordinary cant to the transom.

When the boat is level, or floating level, the motor needs to be as near vertical as possible.

This is when he should measure the height of the plate/hull.
And he should make the motor vertical before hammering the throttle.



This may help him.

If it doesn't, have him lower the motor a hole or 2.

 

[high'n'dry]

Re: Brand New Boat and Motor and won't plane out.

Apparently his new boat was rigged with an engine of the incorrect shaft length is my guess. Too bad, now he has a used boat and used motor that does not work.