Page 1 of 5 12345 LastLast
Results 1 to 15 of 75

Thread: How high to lift the motor

  1. #1

    How high to lift the motor

    My 150 hp Yammie is at its highest setting yet it gets buried in the water, the vessel in question is an Allison Vision 195. I have two options, build up the transom on the pod, it can be done but as there are a few cracks appearing where the pod is bolted onto the transom or use a jacking plate which will push the motor out another 100mm or a third option is completely rebuild the pod. What I am trying to work out is how high to lift the motor, I'm thinking around 40 to 50mm, any ideas on how to solve this issue would be welcome.
    Attached Images Attached Images

  2. #2
    Ausfish Gold Member 552Evo's Avatar
    Join Date
    Jul 2016
    Location
    Melbourne

    Re: How high to lift the motor

    Obviously my hull and motor are different, but these are the 2 points (highlighted) that are level on my standard setup.
    Hope I've understood your question.



  3. #3

    Re: How high to lift the motor

    Ask Moejoes. He's got all the answers

    Just don't ask him how much fuel to carry..........

  4. #4

    Re: How high to lift the motor

    Quote Originally Posted by 552Evo View Post
    Obviously my hull and motor are different, but these are the 2 points (highlighted) that are level on my standard setup.
    Hope I've understood your question.


    Thanks EVO, how far back is the transom, your motor does appear to be much higher than mine in relation to the pod although you must have a very low trailer with your leg that close to the ground. Do you drive your boat on, with mine I do have to trim it out a fair way so with the extra height it will give me more leeway. There are formulas available based on the distance from the transom to the prop which is around 1 inch per foot or 25 mm per 300 mm so around 35mm, however I was hoping someone else had a similar issue and resolved it as I think it can probably go at least 40mm or maybe a little more. As mentioned I'm as high as I can go without modifications

  5. #5

    Re: How high to lift the motor

    Quote Originally Posted by Back In Black View Post
    Ask Moejoes. He's got all the answers

    Just don't ask him how much fuel to carry..........
    Tony I think it was the good weather we had, the fuel evaporated quicker as we were flying and at that altitude we didn't know we had to reset the gauges.

  6. #6
    Ausfish Gold Member 552Evo's Avatar
    Join Date
    Jul 2016
    Location
    Melbourne

    Re: How high to lift the motor

    Quote Originally Posted by Dignity View Post
    Thanks EVO, how far back is the transom, your motor does appear to be much higher than mine in relation to the pod although you must have a very low trailer with your leg that close to the ground. Do you drive your boat on, with mine I do have to trim it out a fair way so with the extra height it will give me more leeway. There are formulas available based on the distance from the transom to the prop which is around 1 inch per foot or 25 mm per 300 mm so around 35mm, however I was hoping someone else had a similar issue and resolved it as I think it can probably go at least 40mm or maybe a little more. As mentioned I'm as high as I can go without modifications
    If the rain stops here I'll try measuring the distance after I get home from work today.
    Yes I don't normally have the motor lowered that much when it's stored but I took that photo a while ago for my own reference so I could compare the height to others. (I was questioning if I should get more top speed)
    Yes the trailer does naturally sit pretty low and I do drive on/off without any issues.

    So I'll take a measurement for you from the rear face of the transom to the closest point on the prop boss.


    Saltwater fishing, boat mad but has a job that gets in the way.

  7. #7

    Re: How high to lift the motor

    Thanks EVO, I had a look and based on your photos I would need to raise the motor 90mm but I don't think it needs to go that high although that would most likely solve a lot of my problems. I wish it would rain here,it's as dry as can be, definitely need it.

  8. #8

    Re: How high to lift the motor

    Ignore the pod it is irrelevant, except for how far back it moves the engine. You need to look at the relationship between the keel and the engine. Pretty much everyone will tell you that if the engine is hard up against transom the cav plate will want to be in line with or just above the transom. However, the flow starts raising as soon as it clears the transom so as the engine gets further back it will need to get higher and higher. A lot depends on speed and hull shape but conventional theory says the water will come up between 6 and 4:1. So if you pod sets the engine back 600mm then engine will need to be between 100 and 150mm higher than it would be if bolted to the back of the boat.

  9. #9
    Ausfish Gold Member 552Evo's Avatar
    Join Date
    Jul 2016
    Location
    Melbourne

    How high to lift the motor

    Just to follow through with what I offered, the distance as discussed in my previous post is 750mm.

    Edit : That's from the end of the transom pod to the prop boss - 750mm
    From the transom proper to the prop boss is 1000mm.



    Saltwater fishing, boat mad but has a job that gets in the way.

  10. #10

    Re: How high to lift the motor

    Thanks Chris, most theories I've seen are probably a little more conservative, 1350 mm as i have calculated out to 112mm but I've only got 80 mm, 150 mm would be great. A jacking plate would put the motor back another 100mm and I'm trying to resist that as on the trailer it already has too much weight on the rear, still something else I'm battling. I have thought a 15mm ally plate bolted on the back might do the job or modify the transom which is a little more work.

  11. #11
    Ausfish Bronze Member Marchy001's Avatar
    Join Date
    Oct 2010
    Location
    Ipswich

    Re: How high to lift the motor

    I had similar issues not being able to lift the engine high enough on the transom. A 3" jack plate from Vance manufacturing in the states fixed it up for me. Much much easier to fine tune engine height. Was sub $300 from memory delivered.

    http://www.vancemfg.com/Contest.html

  12. #12

    Re: How high to lift the motor

    On your photo you've shown a dimension of 1350 to the front of the prop. Measuring along the base of the pod how "thick" is it? that is the important dimension. I'm guessing its 600 or 700mm

  13. #13

    Re: How high to lift the motor

    Quote Originally Posted by Marchy001 View Post
    I had similar issues not being able to lift the engine high enough on the transom. A 3" jack plate from Vance manufacturing in the states fixed it up for me. Much much easier to fine tune engine height. Was sub $300 from memory delivered.

    http://www.vancemfg.com/Contest.html
    Looks quiet good. Will certainly think about it.

  14. #14

    Re: How high to lift the motor

    Quote Originally Posted by Chris Tucker View Post
    On your photo you've shown a dimension of 1350 to the front of the prop. Measuring along the base of the pod how "thick" is it? that is the important dimension. I'm guessing its 600 or 700mm
    Chris, the pod is 730 mm long and each angled side is 280 mm wide.

  15. #15

    Re: How high to lift the motor

    Do a search for some of Jabbas posts Sam. He did a lift on his Seafarer with a heavy gauge alloy plate (looked to be about an inch thick). Lot less additional setback than a Jacking plate - just not as easy to make fine adjustments. Ideally you should find a brave soul to try and get a look at the leg once you are up on the plane and trimmed out to see if you can get any idea as to where the anti-vent plate is sitting in relation to the water hitting the motor - might give you a bit better idea if you can actually see with all the water flying around. Rule of thumb is it should be just skimming the water for best performance - just bare in mind some props don't like running that high.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Join us