04-06 390/40 sundancer. DIESEL Question

Discussion in 'General Discussion' started by see ray, Feb 14, 2018 at 4:16 PM.

  1. see ray

    see ray Member

    188
    Sep 28, 2008
    Sandusky ohio
    LOVE MY BOAT.
    8.1L Mercs
    V Drives
    hi another question on this boat, I'm looking at buying one, with diesels , I never had diesels and what can I look for and expect ( I'm getting a Surveyer , for boat, and motors ) , what is the dependability of these Cummings OSB380 deisels in this boat ,

    Compared to gas how does the boat plane and handle, the boat is fresh water
    I'm also worried about maintainance VS the gas motors

    I was told that these motors were injector problematic, ? At this point it's here say , I would like to know as much about the boat and motors , you can tell me !
    Thanks Jim
    If nessesary Pm me
     
    Ctsearay likes this.
  2. midexp

    midexp New Member

    21
    Oct 5, 2016
    Harrison Township, Michigan Lake St.Clair
    1999 40' Sundancer
    454 merc
    I like you was also worried about not only the maintenance, but the cost if I had to replace a diesel engine (or even to repair). I bought a 1999 40 DA with gas. If I had diesel and one failed, I'd probably shoot myself. Plus I went on boatdiesel.com and read some horror stories. To big of a risk for me. If you got the $35K to replace, go with the diesel.
    BTW, I cruise about 23MPH at 3300 RPM and get about 0.7 MPG.
     
  3. NotHerDecision

    NotHerDecision Active Member PLATINUM Sponsor GOLD Sponsor

    906
    Jun 28, 2016
    Houston, Texas
    2001 Sea Ray 460 Sundancer
    2014 Seadoo 155 LTD
    2105 Seadoo 130 SE
    2013 Mercury Dinghy
    Cummins 6CTA 8.3L
    Cummins diesels are they least expensive to service. The expert is Tony Athens at sbmar.com or boatdiesel.com.

    This is an age old argument but as a general rule diesels outlast gas engines, have much higher torque at lower rpms, don’t have an explosion risk or co risk and handle better around the docks.

    Gas engines are less expensive. Typically you can’t make up the difference in cost of a diesel over gas while using the boat but they almost always pay for themselves at the point of sale as they depreciate less.

    Anyway a 400 can be had either way and both can fit specific needs.

    Are you running in open water or inshore? Do you plan to take long trips? Do you want to run a generator overnight without worry... we need more info for sure.

    Midexp says he is scared of a failed diesel but I would argue most diesel failures are top end related which cost wise is on par with replacing a gas engine. As always, maintaince is the key to both.
     
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  4. RollerCoastr

    RollerCoastr Well-Known Member

    Nov 15, 2007
    Cedar Point, OH / Miami, FL / MacRay Harbor, MI
    1997 400DA
    340HP 7.4 Mercruiser Bluewaters
    Garmin 8212, 741 24HD, Intellian I2
    1999 280BR
    Twin 250HP Merc 350 Alpha Ones
    Do you have fuel meters? I aim for .74 - .75 sMPG. Unless she's heavily loaded or in adverse conditions, I can get it. My old plotter could only calculate to the tenth, so .75 showed as .8. It was a lie and I knew it, but it made me happy. :)
     
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  5. see ray

    see ray Member

    188
    Sep 28, 2008
    Sandusky ohio
    LOVE MY BOAT.
    8.1L Mercs
    V Drives
     
    Ctsearay likes this.
  6. see ray

    see ray Member

    188
    Sep 28, 2008
    Sandusky ohio
    LOVE MY BOAT.
    8.1L Mercs
    V Drives
    Running the boat up in the Great Lakes my longest trips would be about 2 1/2 hours going and 2 1/2 hours coming, probably every other weekend so the diesels would be beneficial for fuel wise
     
  7. midexp

    midexp New Member

    21
    Oct 5, 2016
    Harrison Township, Michigan Lake St.Clair
    1999 40' Sundancer
    454 merc
    No fuel flow meters. I was estimating. I did have fuel flow meters in my last 37' DA with 7.4L carburetors and I got about .75 MPG (actual) at 23MPH and 3300 RPM. So same speed and RPM so guessing a little more fuel consumption. I do want to get the Fox Marine set up to determine actual fuel consumption.
     
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  8. RollerCoastr

    RollerCoastr Well-Known Member

    Nov 15, 2007
    Cedar Point, OH / Miami, FL / MacRay Harbor, MI
    1997 400DA
    340HP 7.4 Mercruiser Bluewaters
    Garmin 8212, 741 24HD, Intellian I2
    1999 280BR
    Twin 250HP Merc 350 Alpha Ones
    I have Garmin GFS-10’s. I can’t say I regret them because Fox gateways didn’t exist at the time, but it would be nice to have the additional data.
     
  9. NotHerDecision

    NotHerDecision Active Member PLATINUM Sponsor GOLD Sponsor

    906
    Jun 28, 2016
    Houston, Texas
    2001 Sea Ray 460 Sundancer
    2014 Seadoo 155 LTD
    2105 Seadoo 130 SE
    2013 Mercury Dinghy
    Cummins 6CTA 8.3L
    I doubt seriously you can get .75mpg on plane in a 400 gas boat. I’ll bet it’s more like .4mpg. Anyway with the runs you are going to do diesel makes since to me.
     
  10. RollerCoastr

    RollerCoastr Well-Known Member

    Nov 15, 2007
    Cedar Point, OH / Miami, FL / MacRay Harbor, MI
    1997 400DA
    340HP 7.4 Mercruiser Bluewaters
    Garmin 8212, 741 24HD, Intellian I2
    1999 280BR
    Twin 250HP Merc 350 Alpha Ones
    [​IMG]
     
  11. RollerCoastr

    RollerCoastr Well-Known Member

    Nov 15, 2007
    Cedar Point, OH / Miami, FL / MacRay Harbor, MI
    1997 400DA
    340HP 7.4 Mercruiser Bluewaters
    Garmin 8212, 741 24HD, Intellian I2
    1999 280BR
    Twin 250HP Merc 350 Alpha Ones
    Why would you believe that?
     
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  12. Bop

    Bop Member

    180
    Sep 3, 2013
    Georgian Bay/Lake Huron
    2001 410 Express, Highfield DL350 w/40hp Yamaha
    Cat 3126
    I have a friend with exact same boat and we run together all the time. Lots of trips well over 180miles trip. He always gets in the 0.5mpg range. I get double that. We both run at the same speed around 23-24 mpg.
     
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  13. NotHerDecision

    NotHerDecision Active Member PLATINUM Sponsor GOLD Sponsor

    906
    Jun 28, 2016
    Houston, Texas
    2001 Sea Ray 460 Sundancer
    2014 Seadoo 155 LTD
    2105 Seadoo 130 SE
    2013 Mercury Dinghy
    Cummins 6CTA 8.3L
    If that’s true fuel consumption measured manually at fill up then you should keep that boat forever.
     
  14. RollerCoastr

    RollerCoastr Well-Known Member

    Nov 15, 2007
    Cedar Point, OH / Miami, FL / MacRay Harbor, MI
    1997 400DA
    340HP 7.4 Mercruiser Bluewaters
    Garmin 8212, 741 24HD, Intellian I2
    1999 280BR
    Twin 250HP Merc 350 Alpha Ones
    I run light because the data provides the safety margin that the fuel gauges don’t. By the time I actually fill the tanks maybe once a summer, I can predict the amount needed within several gallons.

    His boat has issues. Tell him to join CSR. We’ve seen it before: a 410DA running slow, sucking fuel like a MoFO, and even blowing engines and getting teased / ridiculed by his diesel friends. His props were wrong.
     
  15. RollerCoastr

    RollerCoastr Well-Known Member

    Nov 15, 2007
    Cedar Point, OH / Miami, FL / MacRay Harbor, MI
    1997 400DA
    340HP 7.4 Mercruiser Bluewaters
    Garmin 8212, 741 24HD, Intellian I2
    1999 280BR
    Twin 250HP Merc 350 Alpha Ones
    20 years so far, so apparently that’s the plan!
     
  16. Robski97

    Robski97 Active Member PLATINUM Sponsor

    Jan 15, 2007
    North Bellmore, NY
    44DA
    Cummins QSC 8.3's
    U cant compare diesel vs gas in this boat . I actually ran a 39 dancer with SHO gas and what ever diesel was in that year. Ive posted it before the gas was a dog every aspect with a fully loaded boat. Now mind u this was in a bay... no ocean, no real waves only slop. She was slow to respond in gas needed lots of throttle. The diesel version handled much better. BAY TEST both. The boat also came in a NON SHO version... Don't even think about that option unless u want to be a trawler.

    Rob
     
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  17. RollerCoastr

    RollerCoastr Well-Known Member

    Nov 15, 2007
    Cedar Point, OH / Miami, FL / MacRay Harbor, MI
    1997 400DA
    340HP 7.4 Mercruiser Bluewaters
    Garmin 8212, 741 24HD, Intellian I2
    1999 280BR
    Twin 250HP Merc 350 Alpha Ones
    Let’s take a closer look at this. Spit the difference and say 23.5 sMPG, returning .5 sMPG. That means he’s burning FORTY SEVEN gallons per hour?!? Has no-one questioned that during your several hundred mile journeys???

    On second thought, don’t encourage him to join CSR. He should get out of boating.
     
  18. RollerCoastr

    RollerCoastr Well-Known Member

    Nov 15, 2007
    Cedar Point, OH / Miami, FL / MacRay Harbor, MI
    1997 400DA
    340HP 7.4 Mercruiser Bluewaters
    Garmin 8212, 741 24HD, Intellian I2
    1999 280BR
    Twin 250HP Merc 350 Alpha Ones
    Let’s run those numbers. At a reasonable 23.5 mph, that would mean a burn of 58 gallons per hour. That’s totally possible, provided the Mercs have been replaced with steam turbines that use 89 octane and you drag the anchor.

    This is making me grouchy.
     
    Great Lakes likes this.
  19. JVM225

    JVM225 Well-Known Member

    Apr 8, 2008
    Farmingdale, NY
    2002 410 Sundancer, Monaco Edition.
    3126 Cats.
    I think the 04-06 390/400’s are closer in size and weight to the previous generations 380’s than they are to the late 90’s earlier 2000’s 400/410’s.
    The gas motors are way more common in those 380’s than diesels.
    That being said: I love my diesels. You may pay more for the boat with diesels up front, but you’ll save fuel while you own it and it will sell for that much more when it’s time to move up. It will probably sell faster too because buyers for boats with gas motors in that size class are a rare breed.
    That was one of several things I considered when I shifted gears from shopping for a 380 to shopping for a 410.
     
    Last edited: Feb 17, 2018 at 2:07 PM
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  20. Zach312

    Zach312 Member SILVER Sponsor

    394
    Jan 23, 2011
    Hudson, WI
    2008 47 Sedan Bridge, 2013 Caribe D11
    Cummins QSC-600's
    We owned a 2007 40 with QSB 425's. I would strongly encourage anyone looking in this size range to go with diesel power.
     

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