420/44 DB Owners Club

Tenacious · May 16, 2023

craigswardmtb said:
Does anyone successfully run with a 12' dinghy off of the stern of the boat? I'm wondering if it might be too wide where bouncing off pilings becomes an issue. Currently I run with a 10'6" achilles rib with 20hp short shaft Tohatsu in the fully upright position. I have about a foot it looks like and if I lower the motor, I'm thinking I could gain another 4-6 inches. So I'm right on the cusp of 12' being a good fit. Any experience with a larger dink on a 420 or 44db? I have been eyeing a rigged 12' aluminum Inmar in Hypalon with 25hp Suzuki.

I think we may have met in the past. I'm at Mystic Downtown.

I have a Highfield 360 CL with FCT (console) and 25 HP Yamaha on a Hurley H3O lift. Dinghy is 11'10" and I have no problem and that is with OB trimmed down. Beam of dinghy is 5'7" +/- so it's tight on the stern unless you have a submersible lift or platform extension. I installed a Hurley system H30 which is good for up to 400 pounds. I'm on the edge of that but no issues. I use the electric winch option which is a must have. Hind site being 20-20, I should have got the H30 Plus which handles up to around 700 pounds. They also have a new one called the XL. The latter two enable loading jet skis or heavier tenders. Putting a 12" RIB behind your boat on you integrated swim platform will preclude you from being able to open the rear storage area though. It is for that reason that I bought the H3O extension. Based on your boat pic it looks like you may have a lift or platform already. Go for it!

craigswardmtb · May 16, 2023

Tenacious said:
I think we may have met in the past. I'm at Mystic Downtown.

I have a Highfield 360 CL with FCT (console) and 25 HP Yamaha on a Hurley H3O lift. Dinghy is 11'10" and I have no problem and that is with OB trimmed down. Beam of dinghy is 5'7" +/- so it's tight on the stern unless you have a submersible lift or platform extension. I installed a Hurley system H30 which is good for up to 400 pounds. I'm on the edge of that but no issues. I use the electric winch option which is a must have. Hind site being 20-20, I should have got the H30 Plus which handles up to around 700 pounds. They also have a new one called the XL. The latter two enable loading jet skis or heavier tenders. Putting a 12" RIB behind your boat on you integrated swim platform will preclude you from being able to open the rear storage area though. It is for that reason that I bought the H3O extension. Based on your boat pic it looks like you may have a lift or platform already. Go for it!

View attachment 144471 View attachment 144472 View attachment 144473

Yes we did meet on Block if I recall. I'm at Mystic shipyard. Great info. I do have a sealift platform so should have no problem with hatch access. I probably could use some bigger trim tabs though once I put all that weight back there....

Tenacious · May 16, 2023

Tenacious said:
Now that I know what to specifically look for, this should be a snap. Thanks again!

Update on solenoid.

No dice on the fuses being bad but the new Intellitech Little boy did the trick! Wish all issues could be this easy to repair.

LITTLE BOY 100 AMP Latching (Used for Windlass and Generator. (Center generator rocker switch.)
Intellitec 01-00055-000 100amp Latching Relay
Sea Ray Part #: 644609
https://intellitec.com/battery-disconnect-100a/

BIG BOY 200 AMP Latching
Intellitec Part #: 00-00507-712 (Marine Application)
Sea Ray Part #: 980227
https://intellitec.com/battery-disconnect-200a/
*Marine models have stainless studs for the 2 #10 coil terminals.

Both sold on Flounder Pounder but I got the Little Boy from Amazon for $59.:

https://www.amazon.com/INTELLITEC-0...ocphy=9003187&hvtargid=pla-500871443515&psc=1

Bruce SEA 993 · May 17, 2023

Has anyone installed a venturi vent on the 42/44 boats. We had one on the 380 and it was nice to be able to get some air through the helm. We do not have A/C on the bridge and do not really need it in the Northwest. It would be nice to let some air in while running. Was thinking of some hatch vents that would be manually operated.

They could be cut into the plexiglass venturi on either side forward of the wheel.

Cheers!

RBB · May 18, 2023

Our 2006 qsc 500 44db turns 2680 rpm at wot.
Does that sound right?

AEO · May 18, 2023

RBB said:
Our 2006 qsc 500 44db turns 2680 rpm at wot.
Does that sound right?

This is mine and some info from a Cummins guru:

RBB · May 18, 2023

So what is max rpm cruising for all day?
2150 2250 2400 ?

bajturner · May 18, 2023

RBB said:
So what is max rpm cruising for all day?
2150 2250 2400 ?

The rule of thumb I have used is 80% of max RPM, which is 2680, so about 2140 or less.

Note that according to measurements I took on my boat a few years ago, once you reach about 1700RPM, performance wrt fuel economy is essentially linear (flat) all the way to WOT.

bajturner · May 18, 2023

AEO said:
This is mine and some info from a Cummins guru:

View attachment 144605
View attachment 144606

These numbers are pretty much identical to mine, except your oil pressures are lower by 12psi or so (both port and starboard).

AEO · May 19, 2023

bajturner said:
These numbers are pretty much identical to mine, except your oil pressures are lower by 12psi or so (both port and starboard).

I have always had a 10 psi split but never really followed up on it.

bajturner · May 19, 2023

AEO said:
I have always had a 10 psi split but never really followed up on it.

The 10psi delta is normal on the 44DB; it is the same on my boat. It is apparently due to extra oil plumbing on the port engine to bring the oil filter to the inboard side.

AEO · May 19, 2023

bajturner said:
The 10psi delta is normal on the 44DB; it is the same on my boat. It is apparently due to extra oil plumbing on the port engine to bring the oil filter to the inboard side.

Thanks. That makes sense. I’d be interested to know what oil pressures other owners with QSC’s are experiencing...

NorCalRobert · May 20, 2023

craigswardmtb said:
Does anyone successfully run with a 12' dinghy off of the stern of the boat? I'm wondering if it might be too wide where bouncing off pilings becomes an issue. Currently I run with a 10'6" achilles rib with 20hp short shaft Tohatsu in the fully upright position. I have about a foot it looks like and if I lower the motor, I'm thinking I could gain another 4-6 inches. So I'm right on the cusp of 12' being a good fit. Any experience with a larger dink on a 420 or 44db? I have been eyeing a rigged 12' aluminum Inmar in Hypalon with 25hp Suzuki.

I have a Zodiac 360 Yachtline on my hydraulic lift and is fine. Here is the link for specs https://www.boatspecialists.com/zodiac-yachtline-360-yamaha-outboard-yl360-2023/

RBB · May 22, 2023

My WOT Rpm is 2680. My VesselView is showing only 59% load on the engines at 2240 rpm, when I was using smartcraft it was close 80%.
I am thinking it’s not set up correct.
installed a new set of identical props and lost speed. could that be because it is not cupped the same or something

Bruce SEA 993 · May 23, 2023

About 3 weeks ago, the cockpit beverage fridge was discovered to be inop. I had an internal debate whether to repair or replace. I had a swag at the cost to repair of about $600. The fridge was not that old according to the previous owner. It was an Isotherm and about 1.5 cu ft. Miniscule in my opinion. And since these cockpit fridges are very prone to contents leakage, I was thinking of a larger fridge. I keep having to reload it....

Sure Marine Services in Seattle has a web page with all the sizes and capacities in basically a spreadsheet. Nice to use to see what fits.

I mentioned the dilemma to the Admiral and she thought bigger was better as it would open up space in the galley fridge.

So I got a NorCold NR751BB that is 2.7 cu ft so quite an increase.

It fits barely between the stair rail and the curve on the face of the fiberglass corner. I still need a trim strip at the bottom. I think it is an optional item.

Here is the hole:

The new fridge projects about 20 1/2 inches and clears that big wire bundle....barely. I am thinking about pulling it back out and putting a chafe guard on the edge of the fridge where the wires are. It is not sharp but I think I would feel better.

I cut about 1 1/4 inches on the sides and about 3/8 on the top to make the hole large enough. Interestingly, the face of the fiberglass is not perpendicular to the floor of the cockpit. It has a slight taper...likely to be able to get the section out of the mold.

Cheers!

boaterholic · May 23, 2023

Do you recall the exact cutout being what the advertised is?
Thanks

Bruce SEA 993 · May 23, 2023

Cutout dimensions per the owners pamphlet are 20.5 H x 18.5 W x 21 D.

I measured 20.5 deep from the flange to the back of the fridge.

All the dimensions seem accurate as there was no issue getting the fridge in the new opening.

saopm · May 23, 2023

I replaced my fridge this weekend but went with the same size as the old. The new one is flush mount which required cutting about an inch on the left and top. I hear you about the curve by the stairs. I got luck and was able to bend the flange to the contour. It should be easy for you to find a small trim piece for the bottom. Maybe black Starboard and round the edge.

Here is how mine came out.

boaterholic · May 23, 2023

saopm said:
I replaced my fridge this weekend but went with the same size as the old. The new one is flush mount which required cutting about an inch on the left and top. I hear you about the curve by the stairs. I got luck and was able to bend the flange to the contour. It should be easy for you to find a small trim piece for the bottom. Maybe black Starboard and round the edge.

Here is how mine came out.
View attachment 144870

Looks sharp!

NorCalRobert · May 24, 2023

RBB said:
My WOT Rpm is 2680. My VesselView is showing only 59% load on the engines at 2240 rpm, when I was using smartcraft it was close 80%.
I am thinking it’s not set up correct.
installed a new set of identical props and lost speed. could that be because it is not cupped the same or something

Did WOT change from.old props to the new ones?
I had my props worked and went from the factory 24x27 Medium cup to a light cup and went from WOT of 2645 to 2680 which is now in the range recommended for the Cummins QSC motor

420/44 DB Owners Club

Active Member

Active Member

Active Member

Well-Known Member

Well-Known Member

Active Member

Well-Known Member

Well-Known Member

Well-Known Member

Active Member

Well-Known Member

Active Member

Well-Known Member

Well-Known Member

Well-Known Member

Active Member

Well-Known Member

Active Member

Active Member

Well-Known Member

Forum statistics