It is currently Thu Mar 28, 2024 12:33 pm




Reply to topic  [ 3 posts ] 
 Shaft Length Question 
Author Message
MMT Member

Joined: Tue Sep 26, 2017 8:10 am
Posts: 3
Post Shaft Length Question
New to the LTMM game. Got my first one last summer. 6.5 hp on a KKK kit. I am looking to up grade. Found a good deal on a slightly used 16 hp duromax. I am looking at purchasing one of the Thai Style Long tail kits. I have an 85" shaft on my current set up. The length is a little cumbersome. I would like to try to get away with a 65" shaft. I am running this motor on a 14' fiberglass broadbill marsh layout boat. I know its not the ideal mud motor boat but it drafts really shallow and I can still get way with using it in a little bigger water as a layout boat. It has a very low transom height. I was actually thinking about raising the transom height for my tiller motor. I have done my research and learned that the shaft length should reach the wake of boat and that longer shafts lead to lower angles for the direction of force from the prop. Lower angle = more force going forward instead of up. I also read that with the higher angle the prop will want to pop out of the water more and I will have to be physical with it, (Not a huge problem, I play rugby and coach wrestling), or put trip tabs/plates on the rock guard or cav plate above.

Is there away to measure/test to see if I can get away with using a 65" shaft?

Anyone have any experience with a 65" shaft with a 16hp(ish) motor? Was it tough to keep in the water?

Links for Pictures of the boat below.
https://drive.google.com/file/d/0B4wJBG ... sp=sharing
https://drive.google.com/file/d/0B4wJBG ... sp=sharing
https://drive.google.com/file/d/0B4wJBG ... sp=sharing

Thanks for the help.

Cheers,
Pootz


Tue Sep 26, 2017 10:50 am
Profile
MMT Member

Joined: Tue Sep 26, 2017 8:10 am
Posts: 3
Post Re: Shaft Length Question
Took the boat out for a little scouting last night and to check out where my prop hits the water.

https://drive.google.com/file/d/0B4wJBG ... sp=sharing

It looks like the prop is a over a foot past the crest of the wake.


Thu Sep 28, 2017 7:37 am
Profile
MMT 1000 Club

Joined: Mon Sep 19, 2011 6:32 pm
Posts: 1490
Location: south Florida
Post Re: Shaft Length Question
Take a look at the Backwater lite line...they offer both a 65"/55" lengths on the smaller HP motors.

_________________
Sailing in the sawgrass /1648 grizzly and Swomp 26.5 EFI


Thu Sep 28, 2017 11:08 am
Profile
Display posts from previous:  Sort by  
Reply to topic   [ 3 posts ] 

Who is online

Users browsing this forum: No registered users and 111 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to: