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View Full Version : Getting Acquainted with my Blackman



iclypso
11-26-2006, 01:02 PM
As we've only taken the boat out about half a dozen times or so, we're still getting used to who she is and what she does. Our previous boat was a Wellcraft Airslot, which is an incredibly stable boat for its 24 ft length. Because of that, the first time my dad walked from one side of our 23' Billfisher cockpit to the other at speed, it was a little alarming. The combination of the deep-V and the height of the driver's seat above the water made the boat heel a little more than I was expecting. Though it's still a little unsettling when the COG changes, I'm starting to trust the hull and am getting used to fine tuning to level with the trim tabs.

I think the boat is a little over-propped and I plan on going an inch smaller (to 16") to get the revs up a bit and slow down the idle speed. As it is today, I have to bump the boat in and out of gear when slow-trolling sardines. By choice, I've been running around 2850-2900RPM with the AQAD40b/280 combo which gives me a speed of around 15 kts and the engine tops out at about 3200RPM. I think a 3150RPM cruise with WOT ~3600RPM is where the engine should be but I'm not convinced that everything's completely healthy and am hesitant to push it. I hate not being completely confident in my equipment but there's a little more vibration and *clacking* than I would like to hear from the engine compartment and, since the engine box isn't insulated, you can hear EVERYTHING. Sound-proofing the hatch is definitely a high-priority item this winter. We've also noticed an occasional drip from the fuel pump which we were quoted a price close to a thousand bucks to remove, rebuild, replace. The leak is slow enough (~1-2 drop/min) not to affect engine performance and we've put absorbent pads under it but, still, who wants diesel in the bilge? So I'll be rolling my quarters to get that taken care of.

We ran from O'side to La Jolla and trolled for about two hours and burned 37.5 gals. I haven't checked the GPS for the total trip distance but it seems like that should average about 1.75-1.80 miles/gal. Anyone with a similar setup have numbers to compare?

What do you guys do for storage? Has anyone come up with creative solutions? We've been putting our tackle up in the berth and putting the bumpers behind flybridge ladder but I'd love to hear some suggestions.

Moo Fish
11-27-2006, 06:28 AM
I'll take a shot here.....

Do you have a 280 DP?? If so, dropping down to an A3 or A2 may be better than changing prop diameter.

The drip at the injector pump may be with a flared fitting injector line. I had a drip and it turned out to be a flared fitting,

More time on the water and you will get to know every click and clack the boat has to offer.......

NoSlack
11-27-2006, 07:50 AM
You should be running a 16X17 long hub prop and be able to top out at 3600 RPM without overheating. Clogged fuel filters, dirty air filter or a restricted exhaust can all contribute to HP/RPM loss.

When you get those numbers, cruise it at 3100-3200 all day long for a speed in the 18 knot range.

Storage is tough on the 23'. My v-berth looks like I'm holding a swap meet.

Mike

I'll put up some pictures of places to look for your HP loss.

Old Blue
11-27-2006, 05:32 PM
Is probably the right prop. I have a 23 Albacore Special which is the express model of the 23, it does not have the flybridge and is probably a few hundred pounds lighter than your billfisher.

I also have the AQAD40B which is the 165 hp motor. Mine is hooked up to the old 280 outdrive. I currently run No Slacks old prop off of his 23 Billfisher w his old 280 outdrive. Excepting the flybridge and some gear our boats are fairly comparable. So far I'm getting about 2 - 2.5 kmpg per trip. Below are some numbers that I cut and pasted from an old post when I was trying out a few different props. I think you should look for the causes of the lost power / rpms before repropping. Stuff like making sure the controls are pulling the throttle lever on the injection pump all the way open and the notorious rust flake obstruction in the exhaust elbow and or the turbo boost pressure as well as the other stuff already mentioned.

Hope this helps.


"Put her back on the trailer and switched over to Mikes old 16 X 17. I had thought that mike and I were running the same prop back when he had his 280 single prop. Fact of the matter is, mine was not an "elephant ear" but must have been a regular prop because it looked like Mikes had about 30% more blade area.

Headed back out and ran her again. Apparently the tide had started to flow.

2600 14.4 kt ~162 degrees outbound
2800 14.7 kt ~168 inbound 16.0 kt outbound
3000 17.0 kt inbound 18.7 kt outbound
3200 19.6 kt ~178 inbuond 20.7 kt outbound
3400 21.8 kt ~185 inbound
3600 23.6 kt full throttle inbound 24.8 kt outbound

All numbers were taken with full fuel tk and full bait tank and just myself on board. I figure this leaves me about 350 lbs shy of what I would be heading out for tuna since I would have a buddy, 100 lbs of ice and some fishing gear. Looks like the 16 X 17 elephant ear is the right prop."

Nomad
11-27-2006, 06:16 PM
Fight on, USC right where they belong in the #2 spot!

DOGHOUSE26
11-27-2006, 07:14 PM
Jesus Cristo Charlie, it's Monday and you're already into the Margarita Mode!

NoSlack
11-27-2006, 08:24 PM
Here are a few things to look at in your search for the missing RPM.

Pull your exhaust elbow and check for obstructions in the water path. Water dumps in from the top and flows over the stainless exhaust insert. Check the slots at the bottom for chunks of rust. Any restriction in this area will cause a temp increase.

http://www.bocaboard.com/data/500/elbow.JPG

You RPM loss is most likely bad fuel and clogged filters. I think Rich put a new Racor filter unit on last year (at least I remember talking to him about one). Spin the T handle to take the lid off. If the filter looks like it has a film of mud on it, add some diesel fuel stabilizer and change the filters every 10 hours until it cleans up.

Racor filter service link http://www.bocaboard.com/forum/showthread.php?t=348&highlight=racor+filter

One more obscure place to have a fuel restriction is in the mechanical fuel pump. There should be a small filter in there that most people don't know about.

http://www.bocaboard.com/data/500/IM000336.JPG

Old Blue
11-27-2006, 11:07 PM
And if you ever have rust on your turbo, you can bet that the other end of that exhaust elbow, where the stainless insert flares out to seal against the cast iron elbow, has become or never was sealed.

Nomad
11-28-2006, 04:54 PM
Monday is Bloody Mary day. Friday is for Margaritas.