Racing my Tohatsu m40d NEED lower unit gear ratio options?

dalowe

Recruit
Joined
Apr 25, 2017
Messages
2
I am getting into racing these 3 cylinder m40d's and through my failed attempts at finding answers, I felt the need to check with some of you who may have experience with the subject. Other than the stock 1.85? and the 1.1 ratios, is there any other options to change my ratio? I would like a 1.65 to a 1.7 if possible. What other motors have gears or lower units compatible with a M40D? Any help would be much appreciated.
 

Sea Rider

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

Info on the following is needed : which boat is it, is run lightly or not, achieved max wot rpm on flat calm water cond. There are things that can be done to improve performance with little modifications as optimizing OB height and prop maximization.. M40 & M50 both have same 1:85 gear ratio..

Happy Boating
 

TOHATSU GURU

Admiral
Joined
Jul 22, 2004
Messages
6,164
You can get a racing lower unit. Just contact Tohatsu at 214-420-6440 and they will give you the contact information for the guy that builds them in the U.S.
 

dalowe

Recruit
Joined
Apr 25, 2017
Messages
2
I appreciate your help guts. If any of you have any significant experience with racing these motors please get in touch with me as I would love to ask you some questions. I have a worked m40d on a 15 ft aluminum boat weighing 380 pounds without the motor. The rig is running in the 60's but I am never happy.I have the set up pretty close with the jackplate and setback, etc, etc and I have about 10 different props I have collected while enjoying this hobby. Best regards! dalowe1
 
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TOHATSU GURU

Admiral
Joined
Jul 22, 2004
Messages
6,164
Danny Thibodeaux in Louisiana would be your best source for racing stories. Just do a Google search and you should pop up with a contact for him.
 

GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
I appreciate your help guts. If any of you have any significant experience with racing these motors please get in touch with me as I would love to ask you some questions. I have a worked m40d on a 15 ft aluminum boat weighing 380 pounds without the motor. The rig is running in the 60's but I am never happy.I have the set up pretty close with the jackplate and setback, etc, etc and I have about 10 different props I have collected while enjoying this hobby. Best regards! dalowe1

Please - No soliciting and we publicly share information here. It makes the forum work.
 
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