Mounting position for the third log?

[Stamey]

I have purchased a used third log for my 24' pontoon. Unfortunately I do not have any mounting instructions or even know the manufacturer of the log to try and get instructions. There is no writing of any kind on the log.
I have heard you cannot mount it all the way at the back because it will cause the prop to aerate but I may be OK as the farthest back I can mount it would be 4 feet from the rear, due to the engine mount/tray, that slopes up from the engine towards the front.
The third log is about 7.5' long and has L brackets on it for mounting to the bottom of my boat frame.
The motor bracket for my boat starts 4' forward of the back of the pontoons and extends out about 9" from the back of the pontoons.
Pics below.


Will I be OK just mounting it directly in front of the engine bracket?


Thanks,
Chris

 

[5150abf]

Re: Mounting position for the third log?

We make a tri tube option called an express which is that exact thing, difference being we have engineers to figure those things out.

I would mount it as far foward as possible going inline with the rest of the nose cones, you do want some room inbetween the tube and the motor pan.

You are gonna have to run it and see what it does and what you need to do, if anyhting, to get it to run right, even the guys at work usually take a couple stabs at it before they get it but that is the only way to do it, aquadynamics are really funny.

Oh, and I would use a tube,a log will be hard to attach and will waterlog pretty quick, sorry, pet peeve of mine, logs grow in the forest, tubes are made by craftsmen

 

[The Rooster]

Re: Mounting position for the third log?

Don't want to confuse you, "Stamey", but a fellow IBoat member, "Imuss53", did this same conversion w/ a small center log. Do a search for the thread or send him a PM. He actually mounted his short tube just in front of his motor pod, much like the "Pontoon Water Glide" concept. It can cause enough lift to ventilate your prop, but you could remove the back 4 bolts on the motor pod, and add spacers between pod and deck to keep the motor low enough in the water. Good luck!!!

 

[Stamey]

Re: Mounting position for the third log?

Everyone, thanks for the info. I may try to reach Imuss53 to see what he did. I have read the threads where he discusses it.
I may try mounting it forward of the engine bracket, on the next cross member, which is 16" away. This will put the back of the tube at 64" from the rear of the boat.

Thanks,
Chris

 

[Stamey]

Re: Mounting position for the third log?

Well, I tried 5' from the rear. Experienced no aeration of prop, but the turbulence from the outside toons throwing water against the third toon, and what the third toon whipped up, caused the water to be thrown against the bottom of the boat pretty bad. I also could get no more than 16 mph out of it in that position.
Moved it as far forward as I could, to get it out of the wash from the outside toons and it brought the top speed up to 21, but I had 19-20 out of it before, so it doesn't seem to be doing much good.
It's moot now though, as I just found a deck boat that will replace the pontoon boat. Yay!

Just thought I'd update the thread.

Chris

 

[The Rooster]

Re: Mounting position for the third log?

Hey, it was worth a shot. Good luck w/ the deckboat. Send pics !!!