suv17 - etec 40hp tiller numbers

Discussion in 'Prop Shop' started by topnative2, May 23, 2012.

  1. topnative2

    topnative2 Well-Known Member

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    prop- Mich. vortex alum. 13 1/4 x 17p

    3300rpm = 18mph
    4000       = 25mph
    4500       = 28mph
    5000(wot)  = 32mph

    perm. tank 12gal,1pob,tm,battery in stern, no jackplate

    I guess I need to go to a 13p or 15p

    *Stinger electronics automotive meter #3514
    rpm range 30=9000rpm
     
  2. mdiaz707@gmail.com

    mdiaz707@gmail.com I Love microskiff.com!

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    rpm wot range of etec 40 should be between 5500-6000.
     

  3. Creek Runner

    Creek Runner Well-Known Member

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    Etech 40hp is 5000-6000

    http://www.evinrude.com/en-CA/Engines/ETEC_INLINES/ETEC_40_INLINE

    Sounds like you got the right pitch for top end. If you move down to a 15p you will gain about 400RPM's give or take either way. You might gain a MPH or two, but then again you could lose a MPH or 2.

    If blow out isn't a an issue I would raise the engine a hole and retest with the 17pitch wheel.
     
  4. topnative2

    topnative2 Well-Known Member

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    that is an out of the box thought.....  [smiley=1-mmm.gif].... I like it except for coming up w/ a hoist

    I can not trim the motor much  w/o going into porpoising mode ......does that change the thought???
     
  5. Gramps

    Gramps Living & Dying in 3/4 Time

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    Top - rent an engine hoist from the equipment rental place inside of Lowe's, the cost was about $40/day.  I used the lift to remove the tohatsu & install a jackplate.

    Going to a cupped prop created stern lift in my setup, allowing more trim.  Without the cupped prop and stern lift I could trim only a little prior to porpoising.
     
  6. Creek Runner

    Creek Runner Well-Known Member

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    Depends on why the boat is porpoising. Does it do it at WOT trimmed out? Porposing is a very debated topic. It can be caused by many things, trim angle, poor hull design, rocker in the hull, motor to low, wrong prop, weight distribution, and the list goes on and on.

    Raising your motor will allow you to gain some RPM's which will hopefully gain you a couple MPH. It will also allow you to run the engine higher without having to add +trim which could help with the porposing. So yes I would probably still try to raise your engine up. Post a picture of your engine height with 0 degrees of trim in relation to the bottom of the boat.
     
  7. topnative2

    topnative2 Well-Known Member

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    Thanks Gramps good idea on lowes will need to check--- I have absolutely zero boat sources up here. What is a cupped prop?::) ;)

    CR-The motor at vertical(0 negative trim) puts the cavitation plate at 3/4 - 1" above the bottom of the boat. How much do you think it could go up?

    Performance is not a big deal to me . I just want to prop it correctly.It sound like it is screaming now. I am sure a set of tabs would make a diff. but do not want to spend the money. Since, I am fishing in a lake w/ really no rough water

    I am leaning towards a 15p prop w/ the 17 as a spare.What is the rule of thumb for rpm v. pitch

    I have a buddy coming up in June who used to be a OMC test driver and I am going to ply him w/ brewskies for his input.
     
  8. Creek Runner

    Creek Runner Well-Known Member

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    Going to a 15" wheel over the 17' wheel will raise your RPM's by about 400, give or take. So it will be screaming even more, if you think it's screaming now. I wouldn't hesitate to run it to the full 6k range though.
    In theory (rule of thumb) every pitch will = 200 rpm's give or take; depending on many factors.

    In theory a 17" wheel will be faster than a 15" wheel if you can turn the RPM's; as a 19" wheel will be faster than a 17" and so on so on.

    And the exact opposite for out of the hole shot, a 15" will be faster out of the hole than a 17" and a 19"

    The reason for this is because an engine will require less HP to twist a lower pitch prop, however the higher the pitch prop the further you will travel per revolution of the prop IE a 15" prop will move you 15inches forward for every 1 revolution, as where a 19" prop will move you 19 inches for every 1 revolution.

    A cupped prop is where the trailing edge of the blade will have a cup (slight turn upward) which will create more bight, as it does help with lifting the transom it was not originally designed to do so.

    Your motor should be as high as it will allow, without having a blow out issue or low water pressure.
    All this is rule of thumb, the best way is to test multiple set ups, prop, engine heights etc etc.
     
  9. topnative2

    topnative2 Well-Known Member

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    13 3/4 X15p Mich. vortex 3blade

    3000rpm---- 11mph

    4000   -----20mph

    WOT  -   5600-----30mph

    quicker hole shot

    lost speed at top end and thru the rpm range

    Creekrunner was rt. on

    * additional 9lb striper aboard:)
     
  10. Creek Runner

    Creek Runner Well-Known Member

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    Thanks not my 1st Merry go round, lol! only proped probably 800+ boats in my life time.

    Did you ever try moving your motor up 1 hole with the 17P?
     
  11. topnative2

    topnative2 Well-Known Member

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    Nope. I am leaving the 15p on rt. now and seeing how it runs w/ 4pob.

    Next, I will put the 17p on and raise it one hole. I do not believe It can go more based on running observation from a buddy (ex.OMC test driver )

    I will probably stay w/ the 17p for daily use

    I will get some numbers and post.

    thanks for the input
     
  12. lemaymiami

    lemaymiami Well-Known Member

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    No need for an engine hoist to raise the motor one bolthole.... Here's how I've been doing it for years.

    With the trailer not connected to a tow vehicle put the motor all the way down and rest it on two 4x4's. With someone to steady the motor, raise the tongue on your trailer until there's a bit of tension on the motor against those blocks, remove the bolts, then continue raising the tongue (lowering the stern of the boat) until your motor lines up with the next set of holes, re-insert bolts, secure engine then lower the trailer tongue and you're good to go...
    I've done this with much heavier V-4's so a little 40hp should be a breeze....
     
  13. topnative2

    topnative2 Well-Known Member

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    Neat idea.

    I was thinking about using my floor jack

    now I must reconsider [smiley=1-mmm.gif]
     
  14. lemaymiami

    lemaymiami Well-Known Member

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    What I've described is just a shadetree boat riggers solution. You either have to raise the motor or lower the transom (while holding the motor straight as its resting on something that won't scuff up your lower unit. The best part is you don't have to un-rig anything else (wiring harness, steering cable, etc) and it's a quick proposition when you just need to change motor height as you're dialing in your prop.
     
  15. cutrunner

    cutrunner Cert. Yamaha technician

    Thats a good idea.
    The only "problem" i see is getting silicone or 4200 around and in the bolt holes to seal the transom
     
  16. topnative2

    topnative2 Well-Known Member

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    My thought exactly--- Do the top--tighten---do the bottom.

    I ran w/ 15p w/4pob's and found it to be a good match. Good hole shot and a decent crusing speed of 23mph or so.

    definetly the way to go for four
     
  17. tliner

    tliner I Love microskiff.com!

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    you really need to stick with a 15p prop, the 17p is signifigantly overpropped, and no self respecting etec dealer should have rigged that boat to run at 5000 rpm wot

    this link is to the etec owners group, good reading even if your prop worries are solved

    http://www.etecownersgroup.com/post?id=5396435
     
  18. topnative2

    topnative2 Well-Known Member

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    No dealer involvement. I used merc calculator which gave a pich up to 19p.

    The 15p keeps the motor at a higher rpm at all times but increases the rpm required to plane the boat. Also, top speed is reduced and to me it feels like I am running almost w.o.t. all the time which is tiring in more ways than one.

    I like the 17p because it gives on a excellent midrange w/ 2 pobs and the fastest top speed as posted.

    The fact that it barely gets into the recommemded operating range w/ the 17p and its effect on the motor will still be open to honest debate.

    I do believe, after careful observation, that I will raise the motor 1 hole and see what happens w/ the 17p.
     
  19. topnative2

    topnative2 Well-Known Member

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    I raised the engine one hole(3/4") and did not get an increase in speed still at 30mph. I do not think I can go higher because I did experiebce some blowout on a turn when trimmed a little

    However, the boat did plane at a lower speed by about 2-3mph and did not have to trim to get top speed but speed stayed the same.

    Next time I will have the 17p on and the tach.

    We will see.
     
  20. Creek Runner

    Creek Runner Well-Known Member

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    Yeah the going up 1 hole, will only be useful (Maybe) with the 17p. Your already twisting the 15p as hard as she will turn.

    props are all testing, then more testing.

    Good luck