Shadowcast w/ Tohatsu 20HP (Prop Recommendation)

Discussion in 'Prop Shop' started by raydick, Dec 21, 2012.

  1. raydick

    raydick Well-Known Member

    In the market for a prop upgrade for the new ShadowCast. I've read & re-read all the post on the topic here. Thought it best to reach out to the community with my current setup & goal to see if there are any recommendations before I slap on a tach.

    Current setup:
    -2013 Shadowcast
    -2013 Tohatsu 20HP
    -Stock prop (9.25 x 10)
    -Hull weight - roughly 500 lbs (with full tank of gas & gear)
    -Anglers, me 170 lbs, son-120 lbs (fish alone 75% of the time)

    -Find a SS prop that gives best balance of performance in hole shot & top speed for this setup
    -If had to default on one, hole shot is more important (mostly fish shallow & don't run long distances)
    -Would like to keep everything else as is (i.e. no jack plate or cavitation plates)

  2. Well how does the boat run now? If your happy with the holeshot now then stay with the same sized prop but if you want more hole shot go with a 4 blade with less pitch

  3. raydick

    raydick Well-Known Member

    Yes... I want more hole shot. That's why I'm considering upgrading the prop.  Also would like better performance and response in turns & steering - getting some blow out.

    What would be great is a recommendation on a specific prop & pitch to match up with my boat/motor/load that might give me more hole shot & performance in turns.

  4. I have tried 4 different props and 2 motors on my shadowcast the prop by it self doesnt really effect blow out that much, Stock yamaha 9.25x11 3 blade , solas 9.25x10 4 blade , johnson 10x13 3 blade now im running powertech sra-3 10x15 pitch, all the props blow out unless you have the motor trimed wayy down where the boat is riding flat, try driving you boat with the motor trimmed all the way down and you will prob not blow out. I went with a Cmc trim and tilt so I can trim way down to handle good in the turns and being able to trim up on the fly to run shallow and have better top speed. Hopes this helps
  5. raydick

    raydick Well-Known Member

    Yes, it helps a lot. Thanks. Hadn't considered trying to trim down to reduce blowout. I'll give it a try next time out. The CMC looks nice, but out of my budget for now.

    I'm thinking about trying the PowerTech SRT4 (9.5 x 9) - that's a drop in pitch by 1 inch over my current stock 3 blade aluminum. Going with w 4 blade & lower pitch was your initial recommendation. Thanks!!

    From what I'm reading, in theory the 4 blade will give me the performance I am looking for. I'm ok giving up a few mph at WOT to gain the performance on the mid & lower end & hole shot. I'll likely cruise in the mid range and not WOT most of the time anyway.

    Below are some of the benefits of a 4 blade that I got from a write up on the topic. My only question is this. Will the 4 blade give those same benefits on my setup? I guess I'll just have to get the prop and do some testing after the holidays.

    Benefits of 4 Blade
    "increased water displacement capability, lift, and grip .... which translates to... enhance handling, hole shot, low-speed planning ability, cruise efficiency, fuel efficiency, load-carrying performance, ... ventilation/cavitation resistance, motor elevation capability, etc."
  6. No problem make sure to post how that 4 blade does

    GTSRGTSR Well-Known Member

    Bringing this to the top with a few questions,

    what prop are you running now, after your trying different things?

    Where did you buy your prop?

  8. pudding08

    pudding08 Skull Island 16

    The Power Tech SRT is a great prop for those Tohatsu 20HPs. Had the 3 blade on my Gheenoe lt 25 and loved it.