Hi Guys,I've got a 24' toon w/ an '89 120 Evinrude. My plan is to add a third tube. The new 24' tube has some rub thru damage in the side of one section. My plan is to cut a 3-4'section out of the center of the damaged tube and re-weld. This will result in the center tube being a foot or two aft of the other noses once it is mounted, forward of the foot. All the tri toons I've seen have the center tube shifted forward.Does anyone think I'm headed for trouble?I look forward to having you guys share your thoughts on this topic, as I have learned a lot from reading many other threads.Thanks,Hollowoods
I went through this same discussion with a welder friend of mine who works on toons and replaces logs all the time. He also adds 3rd logs. You are right on track the way you want to do it. The only thing I would say is that I don't know how being aft of the other logs will affect things. I would have him mount the log so that the nose is just ahead of the existing logs. Being a little short in the rear will not hurt a bit. You will still gain the lift you're after, even if the log is forward of the transom by a few feet. On my 20'er, he was going to mount a 15-16' log, or even a little shorter, one foot in front of the other logs and let the rear of the log sit about 3' from the beginning of the transom. He said that was the way to go. You do not want it to block water flow to the transom. If your toon is built like mine, the transom mounting protrudes forward of the rear of the boat by about 3'. This means in my case, if I put a 16' log in the middle and let the front extend 1 foot in front of the existing logs, the rear of the log will be 2-3 feet in front of the transom where it begins at the stern. This is good! Even extending it a bit further in the front would be better for water flow to the transom. Remember, the prop has to have unobstructed water flow to it or bad things will happen. Have him mount it 6"-1' in front of the others and it will work out fine.
Hi Hollowoods, heres what I have found by trial and error on this setup. The addition of the third tube does need to be equal or forward of the two outside tubes. Reason is, the inner wake from the two outer tubes will come together in the path of the third tube thus creating as much or more water pressure for the tube to part, hence creating more drag, also the rear of the tube needs to be 3 to 4 feet in front of the leading edge of the lower unit, otherwise it will push the water down somewhat allowing the lower unit to cavitate. Or the tube can be placed directly in front of the lower unit, but the engine will have to be lowered some, thus creating a little more drag. Hope this is easy to understand, I had to move mine once to make it work correctly. Hope this helps.Wayne
Adding third pontoon setup question.
I've got a 24' toon w/ an '89 120 Evinrude. My plan is to add a third tube. The new 24' tube has some rub thru damage in the side of one section. My plan is to cut a 3-4'section out of the center of the damaged tube and re-weld. This will result in the center tube being a foot or two aft of the other noses once it is mounted, forward of the foot. 
Linear Mode
