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Thread: repowering 1856 alweld tunnel

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    Default repowering 1856 alweld tunnel

    So I've been looking around here for some time trying to find some info on what to repower my boat with. Its a alweld 1856 with a tunnel bought from the boat shop new in 07 I believe. Its got a 1992 johnson 115 2-stoke jet, I'm the second owner. I'm looking at the 4-stroke Yamaha 115 jet just kinda conserned about the weight. Just kinda hoping for some pointers i would really like to get better fuel economy which I'm sure anything new is going to do better than what I get which is 10-12GPH ish. But I'm not really wanting to drop to much power to go to like the etec 90 which would be a lot closer to the weight i have now, but i am definatly willing to do that if you guys think my power wont feel that much lacking.
    Just hoping for some help any info would be greatly appriciated
    Thanks in advance.

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    The 115/80 is heavy but a great motor, I had one on a 17.7 Wooly Alaskan, it had a 52" bottom and a tunnel, It would burn about 4 to 6 GPH average.
    I think I figured 3.5 to 5 MPG.
    It seems I needed to run 4400 -4600 to stay on step, suspect the Alweld will be lighter and may do better, that 4" wider bottom will help some too.
    I would not recommend a lift with a narrow bottom, you could consider a Suzi 140, actually a few pounds lighter than the Yammie........but I doubt you could go slow enough to really save on any fuel, but it would haul a load.......Both great engines......You will love the 4S.......I can actually talk to someone in a normal voice......................hope this helps.........
    “Nothing worth doing is easy”
    TR

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    awesome akgramps thats the kinda fuel numbers i was looking for couldnt find much about that yamaha 115/80 on boats my size. that helps a lot. what do you mean by a lift sorry im pretty new to boating in general.
    Thanks

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    Member Akgramps's Avatar
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    You may want a lift if you get a hankering to run a prop, they make the swap much easier, the issue (IMO) is the ~5" setback you get with a lift.
    Moving a 400 pound object aft that much is like a big lever and will make it slower to get on step and will drift lower in the water.....you will lose some performance w/jet by doing so (IMO)....and a jet is 30% less to start with....
    “Nothing worth doing is easy”
    TR

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    oh gotcha thanks. I dont forsee me running a prop anytime soon. thanks again for the info.

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    I do have two threads open that say the same thing i think it was the other thread you said that in. This is my first time posting on this site so I really hope the mods aren't like that over here.

    Sent from my SAMSUNG-SGH-I747 using Tapatalk

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