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SD24 prop questions
Posted: Sun Jul 07, 2019 9:22 pm
by Micks
Hi I am new to the forum and am hopeful for some help. I have 2013 SD24 with 6.2 377 mercrusier with bravo 3 it is all stock with 22.5 4 blade front prop and 22.5. 3blade rear prop. It turns 4800 to 4900 rpms. The problem I have is I can not get any trim out of it at all and it still wants to start porpoising even with the trim as far down as it will go. If anyone has any issues like this please give me some guidance. I did try a set up Hill marine 4 by four Four blade props in a 22 pitch but it did not improve at all Joe with Hill marine suggested trying the same pitch as I am up near my max rpm at Wot. If run the boat at full wide open throttle I can start to bring in some trim but only about 1.0 degree of pitch and if I let off any power at all it will start to slowly porpoise again. I hope maybe some one can help me as we really love the boat as it only has 39 hours on it and is just like new. I am at my end with it and am ready to go back to another brand it has been such a disappointment. Thank you for any input.
Re: SD24 prop questions
Posted: Sun Jul 07, 2019 9:45 pm
by Big Block Power
I don't know if a 3x3 set would help you out then. With duo props you don't need much trim. I noticed this weekend mine was doing that too so I just trimmed it Down a bit no big deal. Mine are 4x4 labbed. This was the first weekend that my trim guage didn't work so I couldn't tell how much it was trimmed up. When it started to bounce I just tapped it down. Or went faster.
Re: SD24 prop questions
Posted: Sun Jul 07, 2019 9:50 pm
by cmattj
Wonder if it’s another bravo drive in the incorrect trim ram holes?
Have any pics of the drive? The should be in the furthest outward Holes.
Re: SD24 prop questions
Posted: Sun Jul 07, 2019 10:13 pm
by akorcovelos
cmattj wrote: Sun Jul 07, 2019 9:50 pm
Wonder if it’s another bravo drive in the incorrect trim ram holes?
Have any pics of the drive? The should be in the furthest outward Holes.
This. I’d bet the last time the drive was serviced they put it in the Bravo 1 configuration.
Re: SD24 prop questions
Posted: Mon Jul 08, 2019 12:48 pm
by no_rulz25
Micks wrote: Sun Jul 07, 2019 9:22 pm
Hi I am new to the forum and am hopeful for some help. I have 2013 SD24 with 6.2 377 mercrusier with bravo 3 it is all stock with 22.5 4 blade front prop and 22.5. 3blade rear prop. It turns 4800 to 4900 rpms. The problem I have is I can not get any trim out of it at all and it still wants to start porpoising even with the trim as far down as it will go. If anyone has any issues like this please give me some guidance. I did try a set up Hill marine 4 by four Four blade props in a 22 pitch but it did not improve at all Joe with Hill marine suggested trying the same pitch as I am up near my max rpm at Wot. If run the boat at full wide open throttle I can start to bring in some trim but only about 1.0 degree of pitch and if I let off any power at all it will start to slowly porpoise again. I hope maybe some one can help me as we really love the boat as it only has 39 hours on it and is just like new. I am at my end with it and am ready to go back to another brand it has been such a disappointment. Thank you for any input.
Good to see another '13 24SD on the forum!! However, can't help with your situation due to having the Volvo 350. If anyone can diagnose your problem it's these boys and girls!! Good luck!
Re: SD24 prop questions
Posted: Mon Jul 08, 2019 9:33 pm
by AsLan7
Micks wrote: Sun Jul 07, 2019 9:22 pm
Hi I am new to the forum and am hopeful for some help. I have 2013 SD24 with 6.2 377 mercrusier with bravo 3 it is all stock with 22.5 4 blade front prop and 22.5. 3blade rear prop. It turns 4800 to 4900 rpms. The problem I have is I can not get any trim out of it at all and it still wants to start porpoising even with the trim as far down as it will go. If anyone has any issues like this please give me some guidance. I did try a set up Hill marine 4 by four Four blade props in a 22 pitch but it did not improve at all Joe with Hill marine suggested trying the same pitch as I am up near my max rpm at Wot. If run the boat at full wide open throttle I can start to bring in some trim but only about 1.0 degree of pitch and if I let off any power at all it will start to slowly porpoise again. I hope maybe some one can help me as we really love the boat as it only has 39 hours on it and is just like new. I am at my end with it and am ready to go back to another brand it has been such a disappointment. Thank you for any input.
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Hello Micks. Welcome to the CobaltChat forum. So glad you found us!
It sounds like your boat is transom heavy or something is out of adjustment. Have you checked the trim rams for anything out of alignment/adjustment? It should not porpoise that much before WOT with the trim all the way down.
Do you have any pics? Are you storing anything heavy back by the transom?
Hope you can figure this out....and welcome aboard mate.
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Re: SD24 prop questions
Posted: Mon Jul 08, 2019 9:51 pm
by Big Block Power
I got this back from the owner of bblades when I asked him that question this was his answer.
Like A7 said something isn't balanced correctly.