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Blow outs and bad porpoise, how do I fix??

Old 09-06-2011, 03:15 PM
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Originally Posted by Fenderjack
If your saying it is plowing, doesn't respond to trim, then a bravo 4 blade is what you are looking for.. They are a bow lifting prop.. Def talk to bblades or throttle up.. I have saw 7 mph from swapping to a diff prob on my stinger...

John jr
It definitely feels like it's plowing and not responding to trim is an understatement! Like I said earlier, anything more than a 0 and the boat picks up a very aggressive and dangerous porpoise!
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Old 09-06-2011, 03:42 PM
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Originally Posted by Rookie
Our boats are similar setups. I had porpoising problems when I ran cleaver style blades, Hydromotive 4 blades. It would try to carry the bow and then it would fall. This turned into bad bow steering and it felt like a death trap. I also had serious issues with props blowing out and could not get on plane with my 3 blade mirages when I first bought my boat. All of the cupping was washed out of my props. My best prop results were adding cupping to my 3 blade mirages (or a Mirage+) or my 2 different style Spinelli's. Round ear blades. I would put on a 25 Mirage+ or a try a 26 Bravo1.
Already have the hydraulic steering and it nice to know that she is that much more stable but really want to try a 4 blade. Just trying to decide if I drop to a 24 or 25? I think a 26 4 blade is going to be a bit big??

Any 4 blades your willing to let a fellow scarab owner borrow for a couple weeks??
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Old 09-06-2011, 05:58 PM
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My 2 cents, if you want to turn 5300 you should be trying 24 Bravo 1's or 25 Mirage or Mirage Plus. Probably gonna want to stick with a bow lifting prop of some kind, not a cleaver as stated before.
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Old 09-06-2011, 06:36 PM
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I agree with the recommendation on 24 pitch 4 blades, I am probably close in weight and power, I have 25 3 blades that run better speed and RPM than my 4's but are very temperamental with taking off I get blow out if I dont ease the throttle and wait for it to get on plane, I have a set of 26 4 blades on it now which shoot the boat up on plane like a rocket no matter how hard you put the throttle down never a blow out, i lost a few mile and hour top end and my rpm is only like 4,600 to 4,700 now so I think the 24 4 blade might be a good fit, I kinda like the 26's on mine because I have increased my speed at cruise.
I also had a pair of 23 mirage plus 3 blades that shot the boat out of the water without any blow out but I hit my rev limiter every time with a few mile and hour slower speed.

Last edited by JWoolever; 09-06-2011 at 06:44 PM.
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Old 09-07-2011, 12:06 AM
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Originally Posted by 502ss
Any 4 blades your willing to let a fellow scarab owner borrow for a couple weeks??
These are the 3 blade designs that have worked best on my hull.
All of my props do cavitate a bit while getting on plane through the 2600-3000RPM range.
Spinelli 4 blade
Spinelli 4 blade round ear
Mirage 25 that has been labbed and cupped.
I should be getting some 26 Bravo 1's in a couple of weeks.
After I finish my testing I could send a pair to your.
Attached Thumbnails Blow outs and bad porpoise, how do I fix??-props.jpg  

Last edited by Rookie; 09-07-2011 at 12:11 AM.
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Old 09-07-2011, 01:33 PM
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Originally Posted by Rookie
These are the 3 blade designs that have worked best on my hull.
All of my props do cavitate a bit while getting on plane through the 2600-3000RPM range.
Spinelli 4 blade
Spinelli 4 blade round ear
Mirage 25 that has been labbed and cupped.
I should be getting some 26 Bravo 1's in a couple of weeks.
After I finish my testing I could send a pair to your.
That would be awesome. I would love to try a 4 blade with minimal or no modifications. This will help me determine where I think I need to be. What pitch are those?

When did you think your testing would be wrapping up? I would love to test before putting the boat away for the season? No pressure though!
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