OFFICIAL 390/40 Motor Yacht Thread

[ManteoMike]

Pretty sure head will have a part number on it, not sure where though. If you ask question on Seaboard website someone will know. Or ask Cummins. In my case engine surveyor was cummins dealer that had replaced the heads, so finding status was easy.

 

[DanH951]

Mike, curious as to whether you found any information on this issue?

Fuel curve is also at sbmar.com.

 

[Mike Veal]

Fuel curve is also at sbmar.com.

Yes , I have this info for the engines. I'm looking for info specific to the 390/40 MY performance

 

[DanH951]

We did have an ex Cummins Tech with lots of years of experience check out the engines and we believe we are OK. During the Sea Trial we ran at 28.3 MPH at 2200 RPMs. Both engines achieved 2650 RPMs at WOT so we believe the engines are propped correctly. Top speed was 32.3 MPH. The engines have 1,080 hours and the Onan Gen has 1,460. I do not know if the engines had any head upgrades or not. I am the 4th owner and by all accounts she is fresh water only on Lake Michigan. We also had a full survey done and have a few items to deal with.

Ray230 VHF Radio handset cords are in bad shape and it appears no replacements exist anymore

I had our Ray230 cord fixed by SeaWire in Ft. Lauderdale last winter. Looks and works great. $204. Home - Seawire Marine

Check the SeaBoard Marine site for more info on the valve issue. There are other ideas on this including the exhaust temp which actually goes down as the engine runs over 2200 rpm. Check more widely on the topic and you'll see other opinions as well.

 

[DanH951]

Yes , I have this info for the engines. I'm looking for info specific to the 390/40 MY performance

Here's mine for what it's worth. 2004 SR 390MY.

 

[Mike Veal]

Here's mine for what it's worth. 2004 SR 390MY. View attachment 139721

Thank you DanH951. Mine closely follows the Cummins 480 CE spec and I'm reducing the prop pitch to reduce the GPH. Curious what changes you did to the boat between Spring 2022 and Sep 2022. Did you re-pitch and if so what prop pitch did you have for both instances?

 

[DanH951]

Thank you DanH951. Mine closely follows the Cummins 480 CE spec and I'm reducing the prop pitch to reduce the GPH. Curious what changes you did to the boat between Spring 2022 and Sep 2022. Did you re-pitch and if so what prop pitch did you have for both instances?

Hi Mike - No changes between spring and September, just adding data to keep track of the boat. The curves are very close to each other. For September, we had full water, 3/4 fuel and our dinghy on the hydraulic swim platform. I went north then south at each RPM. The value in the chart is the average. Prop is 24 x 27 and was tuned and scanned shortly after we bought the boat in July of 2021. I've been in conversation with the shop in Chicago about making a pitch change but not sure I'll do it. They are a little puzzled because you can see at WOT we're under the spec. I imagine you are too. Others have noted that the exhaust temp is the key and if you run up towards 2300 rpm the temp actually comes down. I'm considering adding gages for exhaust temp.
Dan

 

[Mike Veal]

I am having the same discussion with Air Marine. I am taking our 24 x 27 props to 24 x 26 and reducing cup.

 

[bubbles65]

390 MY Hardtop Flexible Solar Panel Configuration:
Has anyone added flexible solar panels to their 390 hardtop? Seems like most 100+ watt flexible solar panels are approximately 4'x2' (1220 x 680 mm) in size. On our hardtop, aft of the hatch, the centreline is utilized by the TV satellite dome, radar, and GPS antennae. Other than those items the rest of the top is clear. Considering placing three 100+ watt panels (total 6?) on either side of the centreline (perpendicular to the centreline) between the hatch and the stern edge. Anyone have any thoughts. Thanks to you all for helping us enjoy another boating season, as we understand our vessel better, and looks sharp.

 

[WAS]

Did they stamp the new head serial number somewhere on the engine or elsewhere? I'm trying to figure out how I can tell if this boat had the heads changed out prior to being sold or by a prior owner. Not too many records from the past owners 2005-2019, just the current owner's records.

I am told by a Cummins tech you should look at the bolts on the head covers. If they look new with no scratches they were never removed. I also had Cummins run my serial numbers and in my case unfortunately, they did not show any worked having been completed by Cummins.

 

[WAS]

I am having the same discussion with Air Marine. I am taking our 24 x 27 props to 24 x 26 and reducing cup.

Same here.

 

[Mike Veal]

Anyone have a Weaver Davit system on their 390/40 MY? We just got a new to us dinghy with the Weaver parts and motor mount system. I need to reposition davits to the swim platform and am curious about access inside the swim platform for bolting. I am planning to use the blind fastener system that Weaver has as my backup plan. I would appreciate any photos. Thanks.

 

[Mike Veal]

I am having the same discussion with Air Marine. I am taking our 24 x 27 props to 24 x 26 and reducing cup.

Repitched props, now 24 x 26, are re-installed. I'll plot the GPH/RPM/Speed in May when we splash.

 

[Mike Veal]

Vetus Thruster 80KGF 24VDC 7.28"ID TUNNEL (aka 185mm dia)
I'm trying to solve a mystery relating to the bow thruster. I was going to order a new anode and the maintenance manual shows a 6-blade propeller. Ours is a 3-bladed impeller. I'm away from the boat to really inspect this, but is it possible the 3 blades were removed to reduce cavitation? Should I replace the propeller to a new 6-blade? I'm curious what others have.
Thanks,

Mike

 

[Irie308]

Vetus Thruster 80KGF 24VDC 7.28"ID TUNNEL (aka 185mm dia)
I'm trying to solve a mystery relating to the bow thruster. I was going to order a new anode and the maintenance manual shows a 6-blade propeller. Ours is a 3-bladed impeller. I'm away from the boat to really inspect this, but is it possible the 3 blades were removed to reduce cavitation? Should I replace the propeller to a new 6-blade? I'm curious what others have.
Thanks,

Mike

View attachment 142315 View attachment 142316

Six blade is the new design and the way to go.

 

[Mike Veal]

Vetus Thruster 80KGF 24VDC 7.28"ID TUNNEL (aka 185mm dia)
I'm trying to solve a mystery relating to the bow thruster. I was going to order a new anode and the maintenance manual shows a 6-blade propeller. Ours is a 3-bladed impeller. I'm away from the boat to really inspect this, but is it possible the 3 blades were removed to reduce cavitation? Should I replace the propeller to a new 6-blade? I'm curious what others have.
Thanks,

Mike

View attachment 142315 View attachment 142316

I received a response from Vetus on this:
The prop has been changed to a 6 blade prop. Part number is SET0088
Anode is SET0150
Shear pin BP228S
Brushes SET0056

 

[KeweeWWG1WGA]

I have a Sea Ray 400 EC which is slipped 300 miles from my house. I am going to change the name of the boat, but forgot to take measurements of the stern area. Does anyone by chance, have the measurements handy?

 

[Mike Veal]

I have a Sea Ray 400 EC which is slipped 300 miles from my house. I am going to change the name of the boat, but forgot to take measurements of the stern area. Does anyone by chance, have the measurements handy?

Try this thread:
http://www.clubsearay.com/index.php...dancer-express-cruiser-official-thread.53469/

 

[Mike Veal]

Cockpit sink slow draining
The small sink in the cockpit of our 2003 390MY drains slowly. I found that it doesn't drain out the starboard side thru hull as the manual implies, but rather to the sump in the ER. The cockpit AC drain hose tees into the sink drain hose in the ER just above the AC raw water pump. No obstruction found in the hoses. Curious if this slow draining is common and what has been tried to fix it.
Thanks

 

[alnav]

Cockpit sink slow draining
The small sink in the cockpit of our 2003 390MY drains slowly. I found that it doesn't drain out the starboard side thru hull as the manual implies, but rather to the sump in the ER. The cockpit AC drain hose tees into the sink drain hose in the ER just above the AC raw water pump. No obstruction found in the hoses. Curious if this slow draining is common and what has been tried to fix it.
Thanks

Mine drains out its own through hull as advertised. I wonder if a PO did the change and if the original through hull is still there? If so, maybe you can put it back. Otherwise, is there a free input on your sump you could route the drain to?