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Duo-Prop Question
#0, Duo-Prop Question
Posted by MAC ATTACK on Aug-19-02 at 02:45 PM
O.K. Guys, spun a prop my last time out and need to buy a new set. What props are you guys running and particularly what duo-props are the guys with the older boats running. Spun a set of A-4s. I am curious to see what speed you guys are running with a full tank of fuel the bait tank full and with two full sized adults onboard. If you know where I could get a set of props without calling Volvo, please let me know.
Mike McCormick/ Mac Attack
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#1, RE: Duo-Prop Question
Posted by SBSRF on Aug-20-02 at 06:42 AM
In response to message #0
Mike, I've done the same thing twice. I now not only carry a spare set of props, but also the hub. You can purchase just the outer prop from Blackmans (I assume you only lost the outer prop). I repowered last year to a AD41, and also run A4's. With a full bait tank and 4 people on board I normally cruise at 18-20 kts. If seas permit I have hit 22-24 kts. I have a very heavy radar arch with a 18 yr old 3' diameter 24 mi furuno radar pod, and that usually dictates my speed in rougher seas. Good Luck.
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#2, RE: Duo-Prop Question
Posted by MAC ATTACK on Aug-20-02 at 07:07 AM
In response to message #1
Thanks Steve, what r.p.m's are you running at cruising speed. Very helpful information.
Thanks
Mike/Mac Attack
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#5, RE: Duo-Prop Question
Posted by SBSRF on Aug-20-02 at 08:45 AM
In response to message #2
Mike, curising rpm is normally 3300 to 3500 for 18-20 kts depending on trim. Max rpm without load is 4000, with load is 3900. So when the seas are kind I've cruised at 3700 downhill/swell at 27-28 kts, what a ride!
Charlie sorry to hear that the bugs are still in. John is the man for the job though. 13 kts is the reason I repowered, we tried everything we could think of but thats all the old AD40 would put out. I'm sure after your next service you'll be able to pull tandem water skiers to the outside. Trim Tabs will definately help. I always try to encourage my buddies to get some rest on the way out just to get some extra weight up front in that v-berth. Good Luck Charlie.
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#6, RE: Duo-Prop Question
Posted by Nomad on Aug-20-02 at 09:34 AM
In response to message #5
My Max was 3500 with the load so perhaps I need to go to the A3's
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#3, RE: Duo-Prop Question
Posted by Nomad on Aug-20-02 at 07:45 AM
In response to message #1
Glad to hear that Steve. This weekend with 4 people and a full bait tank I was making 13 knots at 3500 rpm. I'm running A4's as well. John thinks it may be a clogged fuel filter. Wasn't able to trim it out correctly because of a problem with the tabs. Hopefully most of this will be fixed when the Nomad is in for service.
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#7, RE: Duo-Prop Question
Posted by SBSRF on Aug-20-02 at 06:24 PM
In response to message #3
Charlie, at 12 to 13 kts with my old motor the Grebe would'nt even get up to planeing speed with a full load. Even if I dropped the tabs all the way down I barely got there. We tried A2's thru A5's. Drove me freaking nuts. Thats when I said enough. Get the trim tabs going before you start playing the prop game. By the way if you need a hand changing props, I am certified to change props lying on the swim step blindfolded with one hand tied behind my back.
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#8, RE: Duo-Prop Question
Posted by Nomad on Aug-20-02 at 07:13 PM
In response to message #7
LAST EDITED ON Aug-20-02 AT 07:16 PM (PST)
Thanks Steve. Getting the tabs fixed is my top priority. Bennett has come out with a doel fin tab thats an easy change out for the standard tab. I undersized the tabs on my last boat a bit and called Bennett. They recommended I switch to the doel fin and it was a considerable improvement.
Playing with the props is my last resort but it sounds like I'm falling far short of the performance of the GREBE and other billfishers. John also wants to change out the filters. We'll see!
PS: Thanks for the offer on changing props...sounds like that skill came from considerable experience!
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#10, RE: Duo-Prop Question
Posted by SBSRF on Aug-20-02 at 09:15 PM
In response to message #8
Good luck Baba Lu, fine tuening is a bitch. I know you will get there. Never doubt your choice. Perseverance! Dialing in is the hard part. Also the best education. When its right and you know it, you and you alone dialed into your want, need and desire. My wife would'nt give me that leeway. But the Grebe never said NO! Get my drift. ENJOY!!!
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#11, RE: Duo-Prop Question
Posted by Professor on Aug-21-02 at 05:22 AM
In response to message #3
Charlie
Since A4’s seem to be the standard prop for the well performing 26’ Billfishers I think getting the trim tab, fuel filter and any other power delivery and performance issues out of the way would be in order before changing props. You got my fat rear off the boat Saturday afternoon. That alone should be good for an additional 300 RPM. The engine is also very new.
What are reasons for the doel fin trim tabs? Perhaps Tabman could comment on the Bennett tabs for the Billfishers on this site. His insights on trim tabs one of the other boards appear to be well reasoned and Billfishers all seem to need tabs.
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#4, RE: Duo-Prop Question
Posted by Yellowfin1 on Aug-20-02 at 07:48 AM
In response to message #0
Just purchased the Tenacious a few weeks ago, so I am not 100% sure about the size of my duoprop. The previous owner had the 280 outdrive replaced with a 230. Apparently this allows me to swing an A-9? I have the AQAD40B. With this prop/lower unit/engine combo, I cruise at 3100 RPM at about 14.5 - 15 knots.
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#9, RE: Duo-Prop Question
Posted by MAC ATTACK on Aug-20-02 at 09:13 PM
In response to message #4
I myself am very much like my boat. As I get older the heavier I get and performance goes down. Thinking I might try a set of A-3s. I called Outdrive Exchange, gave him my numbers and he said they are right on. I rarely push my boat over 3200 r.p.m, he says I should run 3500-3700. I tried calling Don but he was unavailable today busy with a new boat in the harbor.
Mike/Mac Attack
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#12, RE: Duo-Prop Question
Posted by Hijole on Aug-21-02 at 05:39 PM
In response to message #0
I spun mine twice. I hit lobster bouy's and rope. Both times I was given a free exchange from VOLVO. I had A-4's now I run A-3's.
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#13, RE: Duo-Prop Question
Posted by moo fish on Aug-23-02 at 01:51 PM
In response to message #12
Did you say free exchange from VP??? How did you arrange this master srtroke? For what it's worth, VP is asking $150 for a tach sensor!!!And I am off to the bone yard to see what's out there.....rt on the MOO FISH
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#14, RE: Duo-Prop Question
Posted by Hijole on Aug-26-02 at 09:08 PM
In response to message #13
When I bought my boat I bought an extra set from Don Blackman(1988). Don replaced both.
I spun and replaced both in about 1993. I never had another problem with them since.
Before I replaced them with A-3's I had one of the A-4 sets reshaped close to an A-3. The prop shop told me that by reshaping the props that I would lose any waranty from VOLVO if I ever spun the set. When I paid for them he had ground out the A-4 stamp from the side of both props.
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