420/44 DB Owners Club

[JNMNL52]

I remember a run of bad shafts back in the early 2000s. Friends repowered two 31 Bertram boats and both suffered broken shafts. Must have been a bad lot number?

Thanks; it is looking that way. According to our parts manual Searay equipped the 44DB with stainless steel AQ22 shafts - so good quality on paper. I do not have confidence in the port shaft so I am replacing that one as well. I do not want to go through that nightmare again. Both shafts are being removed today. I am having two SS AQ22 shafts manufactured as replacements.

 

[Richard Carlisle]

2007 44DB with QSC-500’s. What’s you‘re most economical cruise? I’ve been running at hull speed about 8.5kts burning 8GPH At 120 rpm. Yesterday we did a 2 hour run on the outside at 2200 rpm and 18kts and burned 37GPH.

We are bringing the boat from FL to MD and 8.5 kts on the ICW is getting boring.

 

[Bruce SEA 993]

We have been cruising at about 9 to 9 1/2 mph at 1050 rpm. The GPH are about 7. That is just slightly slower than your speed. It seems the 1050 rpm is right where the fuel burn goes up way faster than the speed. The miles per gallon drop off. Between 12 mph and 18 are no man's land. Might as well go 22 or 24 mph.

 

[Richard Carlisle]

We have been cruising at about 9 to 9 1/2 mph at 1050 rpm. The GPH are about 7. That is just slightly slower than your speed. It seems the 1050 rpm is right where the fuel burn goes up way faster than the speed. The miles per gallon drop off. Between 12 mph and 18 are no man's land. Might as well go 22 or 24 mph.

Thanks. I had this fantasy that there might be a Goldilocks zone where fuel burn and speed came together to create optimal cruise, but I’m seeing about the same as you. Hardly any speed increase between 1200 and 1600 but 3 times the burn.

I would suck it up and pay the fuel bill to run faster offshore, just don’t have any range at those speeds. There are some stretches up up the east coast where fuel is not that easy to find.

 

[Bruce SEA 993]

I'm with you Richard...but I am dreaming too. I think above 1100 rpm, the boat is trying to climb up on plane and the fuel burn reflects that. I get .5 mpg between 1300 and 2000 rpm.

So I stay at the lower rpm most of the time.

There was a chart posted up a long while back in this thread but I do not get anywhere close to the fuel burn on that chart.

We have great scenery here in the Northwest and we enjoy just putting along. When travelling with other boats it is a pain as they were wanting to cruise at 12 knots. That is the worst speed for burn and wake. We would let them get ahead and then blast up to 23 mph for a little bit to catch up.

Going fast up here can be a little crazy though. There are lots of debris in the water from logs to stumps and lumber. we spend a lot of time spotting those.

 

[NorCalRobert]

Here’s a few pics of my GPH etc after I had the props done and changed from a medium to a light cup to run in the range on the chart below.
Seaboard Marine is an excellent resource for info on our motors and proper propping

Proper Propping specs of the Cummins Marine QSC 8.3 500 HP Engine

www.sbmar.com

 

[Richard Carlisle]

80’ Hatteras beside me in the marina burns 122GPH at 20 kts. 48GPH AT 10.5 kts. Captain says it wouldn’t be as much fun as fun if he were paying the bills.

 

[RBB]

Has anyone put an electrical outlet in the bilge? If so where and where did you wire in the power?
Thanks

 

[Irie308]

Has anyone put an electrical outlet in the bilge? If so where and where did you wire in the power?
Thanks

Added two outlets for my pan heaters. Ran power behind the cockpit fridge to new breaker in salon panel.

 

[Bruce SEA 993]

I added one off of the Starboard outlet in the locker by the slider door latch. I use it for the watermaker and then in the winter for the engine room heater.

Edit for Clarity: I taped into the outlet in the locker and ran a new wire to the bulkhead above the Reverso. I used an outdoor receptacle with a cover.

 

[RBB]

I added one off of the Starboard outlet in the locker by the slider door latch. I use it for the watermaker and then in the winter for the engine room heater.

Possibly I could just run a cord down from there

 

[Richard Carlisle]

I have a rail stansion to repair. PO bent the tube and broke the weld from the deck plate. The plan is to cut off the bent tube and sleeve in a new piece, but kneed to remove the deck plate to weld it. So the big question, did the engineers at SR have the forethought to use blind fasteners?

 

[saopm]

I have a rail stansion to repair. PO bent the tube and broke the weld from the deck plate. The plan is to cut off the bent tube and sleeve in a new piece, but kneed to remove the deck plate to weld it. So the big question, did the engineers at SR have the forethought to use blind fasteners?

The pads are through bolted. I just had one of mine welded. Mine was behind the Master Head Mirror cabinet. I drilled a second access hole (inside the cabinet) to reach the nuts. Access depend on which pad is broken.

 

[saopm]

I asked a while back about mounting locations for a rear facing camera. There were a lot of great ideas. I ended up mounting it in the cockpit close to the sliders. I’m going to feel a lot better having an eye on the cockpit and tender while underway. No fiberglass drilling was also a plus.

 

[Irie308]

I asked a while back about mounting locations for a rear facing camera. There were a lot of great ideas. I ended up mounting it in the cockpit close to the sliders. I’m going to feel a lot better having an eye on the cockpit and tender while underway. No fiberglass drilling was also a plus.

View attachment 150883

View attachment 150884

Did that vinyl panel come down?

 

[saopm]

Did that vinyl panel come down?

Yes, I used a plastic pry bar. I Just freed the end I was working on, but the whole thing will come down somewhat easily. My guess, the panel is there to accommodate/conceal the pedestal base for the upstairs table. Otherwise there is finished fiberglass above the panel.

 

[Richard Carlisle]

The pads are through bolted. I just had one of mine welded. Mine was behind the Master Head Mirror cabinet. I drilled a second access hole (inside the cabinet) to reach the nuts. Access depend on which pad is broken.

It the one furthest aft port side. I’m hoping I can get to it behind the couch.

 

[Richard Carlisle]

It the one furthest aft port side. I’m hoping I can get to it behind the couch.

This is the one I’m dealing with.

 

[Richard Carlisle]

Broken prop shaft - Yesterday I had the unfortunate and unpredictable surreal experience of having a bilge full of rushing water due to a broken starboard prop shaft. Beautiful day on the Chesapeake Bay headed north at 20 knots, in 20 feet of water, no obstructions ahead, then bang, the boat slowed down like I hit a submerged object. Bilge pump alarm immediately activated and I stopped the boat to inspect the bilge. I found water rushing in where the starboard shaft used to be and the pumps could not keep up. I grabbed a small hand towel and stuffed it in the prop shaft opening and it was able to slow the leakage. The bilge pumps were able to keep up with the lower leak rate and I limped about a mile to the nearest marina and was immediately hauled out. It appears that the shaft broke clean at the coupling ( possibly due to fatigue) while I was underway during steady state power. The prop was damaged when it hit the rudder - which was the bang noise and the rudder saved the prop. My question is "has anyone else experienced a broken prop shaft in this manner?" The marina service manager who is overseeing my repairs mentioned that Searay had a bad lot of prop shafts in the early 2000's and my boat is a 2006. I would appreciate any comments.

Noticed the other day that my shafts have shaft collars positioned a few inches from the dripless seals. Seemed like a good idea to prevent something like this from potentially sinking the boat. They look like run of the mill 2 piece shaft collars like what you would find at McMaster Carr.

 

[ttmott]

Noticed the other day that my shafts have shaft collars positioned a few inches from the dripless seals. Seemed like a good idea to prevent something like this from potentially sinking the boat. They look like run of the mill 2 piece shaft collars like what you would find at McMaster Carr.

Aren't those the spare seal carriers?