Johnsen 15, 30 Rude prop advice

Discussion in 'Prop Shop' started by Bob_Rogers, Nov 25, 2013.

  1. Bob_Rogers

    Bob_Rogers I Love microskiff.com!

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    '92 hull, full flats deck with platform, troller, 2 batts, etc etc. '88 rude 30 pull start tiller. - Figure 1100lbs with 2 aboard? Current prop is an OMC SS 10 x 15. Tiny tach shows 5200 RPM's , 27 mph top speed.

    I'm looking for a prop that will bring up the RPM's and give better fuel economy at 4000 rpm cruise but still keep WOT speed of at least 25mph. Looking at Solas 12 or 13 pitch.

    Anyone's input who has experience with similar rigs is most welcomed...
     
  2. Dadvocate

    Dadvocate If it ain't broke tweak it a little....

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    I have a 14'-10' Johnsen Skiff rebuilt with front & rear decks. Single side box. 1 series 27 battery and 1 garden tractor battery. 2 guys 225lbs, 5 gals fuel. 2006 Yamaha 25- 2stroke
    10-1/8" x 12 yamaha prop. 28 mph. This is with cell-phone gps and no Tach. Get's on plane with Lenco tabs pretty quick. I extended my transom and shaved it off till stopped cavitation.
    I did have a Solas 10-1/4 x 12 which had a beefier hub but I like this Yamaha prop a little better. Hope this helps.
     

  3. I got a 30 Johnson same motor just different color save yourself some money and have it re pitched at a prop shop and keep the same prop I would do 13 pitch if you want a good medium of top speed and hole shot and 12 pitch if you want more hole shot. You will prob only be
    Going 29 with 13 pitch but better midrange
     
  4. Also cupping helps a lot, my boat was riding very flat and I could only get 27/28 mph at wot so I got heavy tip cup which gave me tons of bow lift and I can run the prop with the top blade out of the water when I'm trimmed out at wot , I can turn 5600-5700 solo and 5500 with two fully loaded to fish. You will get very little gains with prop work I started out 27/28 now I'm at 31/33
     
  5. Bob_Rogers

    Bob_Rogers I Love microskiff.com!

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    Thanks gents -

    LL: why do you prefer the Yammy stock prop to the Solas?
    were you getting cavitation from it?

    SC777: Frank and Jimmy's is very close to me in Lauderdale, so getting my 10 x 15 dialed down and possibly cupped is where I'm headed, but first I want to get the pitch dialed in on an aluminum prop which will then be the spare. F&J can only drop it to 13", so I'm thinking an aluminum 12" Solas would be a worthwhile investment to see how that pitch works out.
     
  6. Dadvocate

    Dadvocate If it ain't broke tweak it a little....

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    I might just be in my head but it seams with the yamaha prop it stays up on plane longer at slower speeds. Don't have tach or real GPS on board so it just seams like that to me. I bought the Yamaha brand new for 100.00 or I would have had the solas repaired at a prop shop to clean it's edges up and check cupping. Side by side the Solas is a lot beefier in the hub.

    No cavitation after cutting transom heigth down twice after recore.
     
  7. southedisto

    southedisto Well-Known Member

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    I'm currently in the process of working out the kinks in my 25 Johnson. I had a Solas new saturn SS 12p 3 blade on it which gave me some cavitation issues on my tunnel hull. Just replaced with a solas amita 4 blade 12p but it will be Thursday before I test it out. If you can wait until then I should be able to give you a pretty good report on the Solas. Just from the looks of it the amita does have more cup than the saturn, which almost has none, and the hub is just as beefy.

    On another note 15p is a lot for a 30hp engine. A stock style 14 or cupped 13 would likely give you better performance. On my 15' CC skiff I have a 50 merc with 14p cupped stiletto prop which gives me WOT of around 35 and good overall performance in the low to mid range. 15p vengence before that had me at close to 40 WOT but poor low to mid.