40 Tohatsu

gcg523

Recruit
Joined
Apr 24, 2015
Messages
2
I have a new 40 tohatsu 4 stroke on a 1652 alweld boat. 6 " set back jack plate. I have been getting a lot of water spraying up the sides of the motor. I keep moving it up with the jack plate and now I'm all the way up? I will go and run it Sunday morning and see how it does. My cav. Plate is above the bottom of the hull about 4 3/4 to 5 ".
Anyone else run like this?
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Welcome to Iboats,

Will boat work without a jack plate, that's engine sitting just on transom ? You are using a long shaft, right ? If so, water flow seems is hittting above the small upper water deflector plate when boat is on plane.

Back Water Splashes.JPG

The only way to address water splashes over or out engine is having a spotter check at which lower leg is water flow passing by at speed, then will know if in need to lower or raise engine. This is tthe sweet height for any Tohatsu engine.

4-Ideal Water Flow.JPG

Trim engine for boat and cav plate to ride parallel to water level once on plane, ideal setting to have spotter check what's going on at back engine.
 

gcg523

Recruit
Joined
Apr 24, 2015
Messages
2
Thanks for the reply. My motor is a short shaft. Its raised all the way up on the jack plate now and I'm still getting water up the side??? My prop shaft is now 3" below the bottom of the hull. I run the marsh a lot so the jack plate is a must
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Can you post a good pic of your actual setup showing rear engine and jack plate. Do you have small side water splashes as first posted pic ? No water splashing over transom, right ? If sitting engine at its correct height on jack plate, will a lower leg skeg protector be of any use for marsh uses ?

If you boat with an engine not well height seated will lose best prop thrust and top 40 HP output, worst if being incorrectly trimmed in/out to compensate water spalshes.

Happy Boating
 
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