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  1. WesNewell

    1957 evinrude fastwin 18hp ventilation problems.

    Yep. I've seen the videos of it doing 24 mph on youtube, but it's on a light weight boat that's rated for a 20-25 hp engine, not your boat that's probably weights 3-5 times as much. What size engine is your boat rated for?
  2. WesNewell

    1957 evinrude fastwin 18hp ventilation problems.

    The height looks pretty good. Now you just need to find the right pitch prop to allow the engine to reach its wot max rpm, which I think is 4000-5000 rpm. But if that boat is rated for a 75 hp engine then you'll be lucky to even get it to plane with an 18 hp. It will surprise the heck out of me...
  3. WesNewell

    1957 evinrude fastwin 18hp ventilation problems.

    From previous photos it appeared that you only needed to lower the engine 2-3 inches to get the av plate even with the hull bottom, but you're saying you lowered the engine 5"? Now I have no idea of where your av plate is in relation to the hull bottom, and that is THE most important factor in...
  4. WesNewell

    Water splashing over transom

    It appears the engine is mounted as low as it can be. He doesn't need a jack plate. He just needs to raise the mounting bolts 2 or more holes to get the lower unit higher and the av plate even or slightly higher than the bottom of the hull line. When done, he will also see an increase in top...
  5. WesNewell

    Water rushing over transom into splashwell

    Probably because the engine was mounted way too low on the transom. With engine in running position on trailer, I think you'll find the av plate below the bottom of the hull.
  6. WesNewell

    1957 evinrude fastwin 18hp ventilation problems.

    https://www.boats.com/how-to/the-outboard-expert-boost-speed-with-outboard-engine-height-adjustments/
  7. WesNewell

    Best prop

    The engine should be raised ~3" from what I can tell from the photo. If you can't do that on the transom, then you need a jack plate.
  8. WesNewell

    1957 evinrude fastwin 18hp ventilation problems.

    You don't want the av plate to be below the hull bottom, so I'd only notch out the minimum amount of transom to accomplish that. If that's 2", then that's all I'd remove. There's no point in removing more than needed. All that will do is weaken the transom.
  9. WesNewell

    1957 evinrude fastwin 18hp ventilation problems.

    Either get a long shaft engine or if you want to keep that one get a jack plate for it that will allow it to get down in the water the proper depth. Or redo the transom height. If you notch the transom down, I'd make a splash well for it to avoid taking on water.
  10. WesNewell

    Other causes for prop slip?

    Most/all? tachs have settings for the engine installed for. If it's not set to the proper setting, then the reading will be off. And I've seen them set wrong from the factory.
  11. WesNewell

    Prop pitch change

    Depends on what your rpm does with the ss prop. As long as it stays within the wot rpm range then it's fine.
  12. WesNewell

    18' pontoon prop?

    Check your manual again. I think you'll find wot rpm to be 5500-6000 rpm. And yes, you should lower your pitch to increase rpm.
  13. WesNewell

    Looking for a prop

    Try this. https://solaspropellers.com/index.php/boat/prop-finder
  14. WesNewell

    distance traveled per revolution

    yes. if you are only talking prop rpm, disregarding gear ratio and engine rpm., or if GR is 1:1. Formulas and calc for it are here. https://www.go-fast.com/Knowledge-base/Find-your-prop-slip/Prop-slip-calculator
  15. WesNewell

    Best prop

    Solas prop finder for 12' tiller boat weighing 250# suggest a 12 pitch amita 3 prop. If you can't get on plane now, and you have the engine at the proper height and tilt, then drop down in pitch 2" and try that.
  16. WesNewell

    Best prop

    The best pitch will depend on 1, the weight of the boat, 2, the gear ratio of your engine, and 3, the weight of the load. Without this info there's no point in guessing.
  17. WesNewell

    2001 Mercury 60hp Bigfoot

    If your boat only weighs 500#, then you are way under propped and your engine is is maxing out rpm to the limiter with only a 15P prop. Merc prop selector suggest 25p for 500# boat and 300# load and speeds over 50 mph at 5800 rpm. Usage: Overall good performance/0 ft Engine Manufacturer...
  18. WesNewell

    2001 Mercury 60hp Bigfoot

    Mounted at the proper height with your boat being under 1000#; you should get ~38 mph with a light load and an 18P prop doing ~5800 rpm. As for a tach, no matter which one you get, make sure it is set properly. This is according to he Merc prop finder. 1000# boat, 400# load, 12 Gal gas.
  19. WesNewell

    2001 Mercury 60hp Bigfoot

    You'll find a good starting point here. https://www.mercurymarine.com/en/us/propellers/selector/#!/step-one
  20. WesNewell

    What is the effect of decreasing Prop diameter?

    Won't hurt your boat a bit. Your engine is another story. It will put extra strain on it.
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