50 tohatsu on IPB with jackplate

Discussion in 'Prop Shop' started by rashouri87, Apr 11, 2011.

  1. rashouri87

    rashouri87 I Love microskiff.com!

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    Hi guys, I've beaten my stock prop up badly already and I'm looking for an upgrade to SS. Here are my specs

    5400-5500 RPM WOT depending on with/against tide.
    currently 13 pitch
    1.85 gear ratio
    350-400 pounds of boat, usually heavy loads (500-700 pound loads)
    top speed lightly loaded with brand new prop = 34 GPS'ed (initial estimates with phone speedo were incorrect)

    I emailed PowerTech and they recommended NREB3 in 12 pitch or SWC4 in 10 pitch, does this seem right??
     
  2. Brett

    Brett > PRO STAFF <

    3 blade stainless with an inch smaller pitch will up the rpm about 200 to 5600 or 5700.
    Sounds good to me.
     

  3. rashouri87

    rashouri87 I Love microskiff.com!

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    won't that decrease my top speed though?

    I'd like to have the same holeshot as its pretty good, esp with tabs and plate, and get a little better top speed.
     
  4. Brett

    Brett > PRO STAFF <

    Should improve hole shot and top speed.
    Stainless allows a thinner blade crossection for less drag.
    Increase rpm, less drag...more oomph!

    Besides, the guys at PowerTech do this for a living.
    I'll bet they know a heckuva lot more about it than we do.

    [smiley=happy.gif]
     
  5. rashouri87

    rashouri87 I Love microskiff.com!

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    lol i know, i know, trust the pro's! thanks for the quick reply, Brett!
     
  6. btomas

    btomas I Love microskiff.com!

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    While I have a Honda 50 on the IPB, heavily loaded with front and rear decks, CC, baitwell, Trolling motor, 12g gas and trolling batt upfront  AND two heavyweight fishermen. Went thru a few props before I settled on the SS NREB3-14 - wot is 5700 rpm and goes about 32.  Great hole shot.  Got several spares from the exercise

    Spare 1- I also tried the NREB3-13p but it maxed out on RPM hitting the overrev limiter.  I had it cupped which dropped RPM down to 5900 with top end of 28-29,  Great hole shot.

    Spare 2 -Then I tried one more prop, the SWC3 -13p.  While this is an ideal prop for shallow running with a jack plate, it was too much prop for the weight of my boat/gear & heavyweights.  I could only get it to 5400 rpm and about 28 mph. but still a great hole shot.

    Bottomline with a heavy IPB- I stayed with the NREB3-14, wot of 5700rpm and 32 mph. I think it is pretty hard to screwup the hole shot with 50hp on the IPB.
     
  7. btomas

    btomas I Love microskiff.com!

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    Ref the Honda 50 reply I just gave, I just looked up the gear ratio, it is 2.08:1 so while it may not be a direct comparison, it does give a relative comparison of those different props.
     
  8. rashouri87

    rashouri87 I Love microskiff.com!

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    thanks for the tips! I think I'm gonna go with the NREB3 - prob 12 pitch, I kept my IPB setup medium on the weight, I have front and rear decks, rear lock box, front bulkhead, Poling platform, casting platform, and TM, with two batteries. No CC, or livewell, generally two heavy anglers, we're hitting mid 30's on most days and 30 with three anglers. I'd like to be able to spin up a little faster with three and get a little more top end with a light load. RPM's listed were tested with just me (260#'s). I heard of some IPB's hitting near 40 with the right prop setup though? makes me wonder what I could get mine to do??
     
  9. adc77

    adc77 Well-Known Member

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    my yam 50 2 stroke has a NREB3 15p. it was the prop off there demo boat (honda 5o carb) i think. i still have not put a tach on it but it does 35 solo down to 30 with more load on gps. that's enough for me however it does sound like its not hitting its top end.

    rum is that 50 a 2 stroke? we have the same gear ratio but i don't know your rpm. my rpm range is 4500-5500 wot. i know our loads are similar.
    please let me know how this ends up.

    and BT,
    when i get a tach i would love meet up. you can try my 15 if i can try your cupped 13. lol
     
  10. rashouri87

    rashouri87 I Love microskiff.com!

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    mullet, mines a DI 2stroke, so its WOT RPM range is higher 5100-5800 i believe?
     
  11. Gramps

    Gramps Living &amp; Dying in 3/4 Time

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    You're correct Rummy; 5,150 - 5,850rpm my 40TLDI is the same.

    http://www.onlineoutboards.com/pdf/owners-manuals/Toh_40_50_70B_90B_TLDI.pdf