Transom Height

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JALL
Posts: 113
Joined: Tue Aug 24, 2010 4:39 am
Location: WISCONSIN

Transom Height

Post by JALL »

The Cruisers Inc I'm working on has a built up transom. The height is 19.5 in. which is about 3.5 more than original. I have two 1957 Johnson 35HP motors to put on it. These motors are not the long shaft models. The question is should I leave the transom at 19.5" or get it back to the original 16"? I almost think the motors would work with the 19.5" Thanks for any help!
Torchie
Posts: 270
Joined: Tue Nov 23, 2010 4:55 pm
Location: Alden, Michigan

Post by Torchie »

I am running twin 57 johnsons on my Thompson.
My transom is about 19 1/2" where the motor mounts. My 35's are the long shaft which leaves me about 15" of lower unit hanging below the hull. Plus the added depth of the hull dispalcement in the water.
Is there any water marks (Pond scum) on your lower unit. if so how far above the water intake are they. That would help tell you how deep they would have to go or at least have been. Hope this helps.
Karl.
Phill Blank
Posts: 412
Joined: Thu Jan 05, 2006 4:20 pm
Location: Hurley, Wisconsin

Post by Phill Blank »

JALL,

If you are going to be running older stadard leg length lower unit outboards, you will need to lower the transom height. The anti-cavitation plate just above the prop, should be at or slightly lower then the bottom of the hull. These older motors with standard leg length are designed to run on a 15" transom height not the taller height for the long leg motors.

Cut it down or find NOS long legs for the motors.

Good Luck,

Phill
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JoeCB
Posts: 241
Joined: Fri Dec 30, 2005 5:17 pm
Location: Farmington Hills , MI

Post by JoeCB »

Remember that transom height is measured along a vertical line, not along the inclined face of the transom.

Joe B
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