Suzuki DF250 prop on Grady 247

PMCbear04

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Anyone run a single DF250 suzuki on a 24-25' Grady? I think my prop needs tweaking. Looking to see if anyone has info. Thanks.
 

theclam20

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I have searched this as well, although i have a HPDI 250 on my 2000 247.

My main complaints are bow rise and wanting to fall off plane around 20-22 MPH.

This is really the only thing i have found. I have tried contacting the poster to no avail.

http://www.thehulltruth.com/boating-for ... tions.html

Again, dealing with 2 strokes. I am not sure if its related to your motor.
 

billfish33

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when I first had my df-300 installed,the prop they originally sent was the 3x16x18.5 , and that was just too much of a pitch for our setup.
The motor at wide open throttle was supposed to be near 6200 rpm , and we were way below that.
they were nice enough to swap the props for us to the 3x16x17 and that got us much closer.

what prop are you running now ? , and what does your book say your rpm's should be at WOT ??
 

PMCbear04

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billfish33 said:
when I first had my df-300 installed,the prop they originally sent was the 3x16x18.5 , and that was just too much of a pitch for our setup.
The motor at wide open throttle was supposed to be near 6200 rpm , and we were way below that.
they were nice enough to swap the props for us to the 3x16x17 and that got us much closer.

what prop are you running now ? , and what does your book say your rpm's should be at WOT ??

3x16x18.5. I'm slow on plane, mainly (I think) due to bow rise and settling stern at initial acceleration. Once finally on plane it operates well. I even get 6000 rpm when I continue to trim the motor up, getting 40+ WOT. I'm happy with that. Just not impressed at all with the holeshot. Thinking maybe a 17 pitch? What does venting do to a prop? Thanks for the input.
 

DennisG01

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I don't have the same boat or the same engine, but the general idea is exactly the same. I have a 15-1/4x17 on my Yamaha and I can get to the top of the RPM range (5,500) at a touch over 40MPH. Is 6,000 the top of your engine's RPM range? For now, I'll assume yes. So, going on that, it sounds like you're propped pretty well and I'm not sure I'd start messing with lower pitched props since you'll over rev your motor at the top end if you're not careful. You'll also end up running a higher RPM at cruise. Tweaking your current prop could help some, but it's only going to be very minor.

-- Make sure your engine is trimming all the way down (physically check this)
MOST importantly:
-- Does your boat have trim tabs? Use those. If not, put tabs on - they will make a HUGE difference in both your hole shot and planing speed.
 

PMCbear04

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DennisG01 said:
I don't have the same boat or the same engine, but the general idea is exactly the same. I have a 15-1/4x17 on my Yamaha and I can get to the top of the RPM range (5,500) at a touch over 40MPH. Is 6,000 the top of your engine's RPM range? For now, I'll assume yes. So, going on that, it sounds like you're propped pretty well and I'm not sure I'd start messing with lower pitched props since you'll over rev your motor at the top end if you're not careful. You'll also end up running a higher RPM at cruise. Tweaking your current prop could help some, but it's only going to be very minor.

-- Make sure your engine is trimming all the way down (physically check this)
MOST importantly:
-- Does your boat have trim tabs? Use those. If not, put tabs on - they will make a HUGE difference in both your hole shot and planing speed.

Thanks. Agreed on trim tabs. I have them and I use them. What seems to be inconsistent to me is where the motor likes to be trimmed during takeoff. If it's all,the way down, it feels like it's inducing extra drag (30" shaft) and as it trims up it seems to help me get to plane quicker. Which to me is counterintuitive. I would think trimmed all the way down (like you alluded to above) would be better to get out of the hole. Where is your motor during Holeshot?