Welcome to the Cummins Marine Community

At Seaboard Marine, we live and breathe Cummins Marine Diesel... the community forum is a place where you can share your experiences, ask questions about your Cummins Marine engines & products, and interact with others in the boating community. Please note that you must be registered on www.sbmar.com in order to create topics in the community forum.

Welcome, Guest! Please Register if you would like to create topics in the community forum.

This forum contains 1,679 Topics, 9,704 Replies, and 5,008 Contributing Members.

Viewing 20 topics - 1 through 20 (of 1,679 total)
    • Cummins Marine Forum Topics
    • 08 QSB’s 400 freshwater hours, aftercoolers never serviced…

      This topic has 1 reply, has 2 voices, and was last updated by dave carey 3 hours ago

      August 18, 2019 at 9:23 am Buddy of mine is looking at a 2008 38’ Sabre with a pair of 400 hour 380 hp QSB’s. The boat has spent its life in the Columbia River in the Portland area where the water is fresh not salt. Pictures show engines that look new with no sign of dirt, grunge, leaking or anything bad at all. My buddy has seen the boat and been aboard for a sea trial. He said that the engines ran like new, showed no signs of overheating and made full rpm’s. The …

      Started by:  Bruce Beard in: Cummins Marine Engines


      1 Reply
      August 18, 2019 at 9:35 am Should be little or no corrosion but they could be plugged with organic stuff. Check the impellers on the sea water pumps see if they need replacing (where on the blade end lobes). Dave C

      Last Post by:  dave carey posted: 3 hours ago

    • flushing 450 cummins with barnacle buster

      This topic has 2 replies, has 2 voices, and was last updated by victor brunst 6 hours ago

      August 16, 2019 at 8:38 am Have a 2004 Tiara 3600 Sovran with twin 450 Cummins. New to marine diesels and doing this maintenance for first time.Trying to flush engines with Barnacle Buster by pumping solution thru heat exchanger and return thru raw water pump connection. All works well water returning from water pump connection but slowly escaping somewhere else. No evidence of leaks or water in the bilge. Have not plugged/isolated water supply to shaft dripless bearings…

      Started by:  victor brunst in: Cummins Marine Engines


      2 Replies
      August 18, 2019 at 6:53 am Thanks again John! Pinched the hose to the bearings and it stopped the leak. victor vb

      Last Post by:  victor brunst posted: 6 hours ago

    • 6bta 5.9 CPL 970 won't exceed 1800 rpm 1 2

      This topic has 24 replies, has 6 voices, and was last updated by Dave Weber 6 hours ago

      July 26, 2019 at 3:34 pm Hi Guys, New to forum and need some help. I’m hoping you can help me out with a problem I am experiencing with my boat engine, Cummins 6BTA 12 valve 5.9 M2 EP-9 injection pump. The problem I’m having is with the port engine which fires up without hesitation and runs great up to about 1800 rpm at this point I can continue advancing the throttle but there is zero response, this all happens under load. In the neutral position the engine…

      Started by:  Dave Weber in: Cummins Marine Engines


      24 Replies
      August 18, 2019 at 6:52 am Hi All, Sea trial result a little better, 2000 rpm, but I’m not so sure it wasn’t the starboard engine dragging up the port. Static boost at 2000 was 5 psi. I’m going to do a “fake boost” test next. I have built the device pictured below so that I can pressurize the aneroid to simulate 20-30 psi boost and maybe I can loosen up the diaphragm if it is stuck. Also, I will be doing a boost leak test and have to build th…

      Last Post by:  Dave Weber posted: 6 hours ago

    • EnviroVent CCV Kit 6BTA Blowby Question

      This topic has 3 replies, has 3 voices, and was last updated by Rob Schepis 1 day ago

      August 13, 2019 at 10:16 am I have purchased two kits for my 6BTA5.9M4 on a Bayliner 4788. The Port engine forward plug is accessible, however the Starboard engine has a Filter assembly bolted where the filter will angle next to the Coolant tank. where can i relocate this to. Also the kit has the bottle connected to the inlet ot the T fitting not the middle? I would have hoped for some basic directions included. Any suggestions?

      Started by:  Charles Matthews in: Cummins Marine Engines


      3 Replies
      August 17, 2019 at 12:32 pm The bracket Tony references may not be on the site at this time that is why he is referring you to reach out to Brendan directly. Rob "Luck is the residue of good design."

      Last Post by:  Rob Schepis posted: 1 day ago

    • Question on Engine/Prop load

      This topic has 8 replies, has 3 voices, and was last updated by Rob Schepis 1 day ago

      August 15, 2019 at 2:57 pm Hello gentlemen. I’ve read your great articles regarding propeller load and engine life. I have a 2005 Sea Ray Sundancer with Cummins QSB 5.9 380’s. First diesel boat and love it. Just got back from a 6 day cruise and paid close attention to my fuel burn as it relates to the performance chart that you reference. At a comfortable cruise power (about 2450-2500 RPM, about 75%load) which yields about 21knots, it seems I’m burn…

      Started by:  marks737 in: Cummins Marine Engines


      8 Replies
      August 17, 2019 at 12:30 pm marks737 wrote: For example…if the same engines and props are driving two different boats. One weighs 20,000lbs and the other 35,000lbs. Wouldn’t the engines on the 35,000lb boat be under a much greater load/fuel burn to achieve the same RPM’s? “Same engines and same props”, well then yes for sure but those two vessels would never use the same gearing/propping. Rob "Luck is the residue of good design."

      Last Post by:  Rob Schepis posted: 1 day ago

    • Best replacement for Racor 1000

      This topic has 2 replies, has 3 voices, and was last updated by Rob Schepis 1 day ago

      August 16, 2019 at 6:44 am I was looking at a new filter set up. I never understood what Racor-it-is was, but now I am disassembling my filters for the second time this year to clean gunk from the bowl. I’d much rather just change an entire spin on filter, and im ready to switch over. I do not have room for a dual filter setup. Has to be one filter. What would be the best option for a Cummins 370. 1990 Blackfin 32 Combi. Cummins 370s 2006 Scout 190 Costa/Mercury 2…

      Started by:  Mike Pettee in: Cummins Marine Engines


      2 Replies
      August 17, 2019 at 9:33 am Can you add this bulk separator ahead of the Racor? https://www.sbmar.com/product/3-premium-extra-duty-bulk-separator-kit-fs19513/ Rob "Luck is the residue of good design."

      Last Post by:  Rob Schepis posted: 1 day ago

    • CMD 2.8 Fuel consumption j1939

      This topic has 0 replies, has 1 voices, and was last updated by Peter Øvad Halkjær 1 day ago

      August 17, 2019 at 7:59 am Hi all I have 2 Cummins Mercruiser CMD 2, 8ES (2006) in my boat. They don’t have smartcraft. Can I export fuel consumption etc. be exported from j1939 via a converter to NMEA2000? Kind regards Peter phk Attachments:You must be logged in to access attached files.

      Started by:  Peter Øvad Halkjær in: Cummins Marine Engines


      0 Replies - Can you Help? ...be the First to Respond!

    • Cooler/Heat Xchanger maintenance

      This topic has 5 replies, has 3 voices, and was last updated by sean b 1 day ago

      August 14, 2019 at 7:13 pm First diesel powered boat. 2 QSM 11’s w/ the manifold leaks and over-propping etc. Working on the prop issue now and this site has been very helpful as far as that goes. I’ve read a lot of info on this site regarding seawater system maintenance but I can’t find anything that gives specific guidelines on the time frame for the maintenance. What is recommended as far as how often to remove and clean coolers/heat XC?? …

      Started by:  sean b in: Cummins Marine Engines


      5 Replies
      August 17, 2019 at 7:44 am Thanks Steve. I appreciate it. sean/searay500

      Last Post by:  sean b posted: 1 day ago

    • O Ring Diameter Conundrum 6BTA 5.9 330hp 1998 Era

      This topic has 2 replies, has 3 voices, and was last updated by Fireisland1 1 day ago

      August 16, 2019 at 1:50 pm I recently serviced the new to me aftercoolers as per the SeaBoard way. They looked in pretty good shape and I had no issues pulling the core and cleaning. I reassembled them using the 3/16 diameter orings though the ones that I took off were the small 1/8″. There didn’t seem to be a lot of squish resistance and the cap and housing met without much force applied. I chose the 3/16 because I read on this forum or perhaps boatdiesel.co…

      Started by:  Frank in: Cummins Marine Engines


      2 Replies
      August 16, 2019 at 6:24 pm When you use the correct o ring, there is minimal interference. You may not even notice it when tightening down the bolts. If you put in too large of an o ring, the gap will be very noticeable and will require significant force to mate the cap to the case. If so this will deform and pinch the o ring.

      Last Post by:  Fireisland1 posted: 1 day ago

    • Shooter the 40 knot Bertram 31

      This topic has 2 replies, has 2 voices, and was last updated by david h witty 2 days ago

      August 12, 2019 at 7:31 am Was wondering if there are any updates on Shooter? she was cruising at 32 knots with Yanmar 6ly2 STP’s and wondered if the engines had lasted . was also interested in details such as EGT,boost, and RPM at that cruise speed. I have a contender 35 with 25 y/o 6ly(m) ute’ s which is reason for my interest. thanks!

      Started by:  david h witty in: Boats & Repowers


      2 Replies
      August 16, 2019 at 10:09 am Thank you Tony Am weighing all my options for possible repower.My boat is obviously old and I don’t think worth it to put in brand new engines.For reasons of simplicity and cost should probably stay with mechanical engines.Qsb 5.9 440 would sure be nice though,but are 8 inches taller than my current engines and likely won’t fit. Good to know the 6ly2 can provide the desired performance and last if used in right application and proppe…

      Last Post by:  david h witty posted: 2 days ago

    • 2007 QSC 8.3 smart craft oil pressure

      This topic has 4 replies, has 3 voices, and was last updated by tombuskirk 2 days ago

      June 20, 2017 at 10:34 am Any help would be appreciated. 2007 qsc 8.3 . 1700 hrs. All was fine until on way home from fishing trip, low oil reassure alarm and low oil code went on and smart craft display said 0 pressure. I took off sender and installed pressure gauge. Pressure was 59 and warmed up at Idle was still in 30s. I purchased a sender locally. Now alarm off started cold but as engine warms alarm and low pressure code come back. Smartcraft reads 69 at anythin…

      Started by:  David in: Cummins Marine Engines


      4 Replies
      August 16, 2019 at 8:45 am I’m having the same issue with my 2007 QSC 8.3. Low oil pressure alert code 415 indicating 0.0 PSI. Towed into Shearwater, BC, pressure manually checked good (70 PSI within 5 seconds of engine start). Having sender unit that Corey’s post indicates flown in today from Vancouver but based on this post and another, I’m not sure this will fix problems. Mechanic here does not think this is a wiring issue, nor the low coolant sensor leaking issu…

      Last Post by:  tombuskirk posted: 2 days ago

    • Low oil pressure fault 415 QSB 8.3

      This topic has 3 replies, has 4 voices, and was last updated by tombuskirk 2 days ago

      June 9, 2018 at 10:39 pm Hi 1600 hours QSB 8.3 Maine Cummings Fault code came up 415 low oil pressure Cummings service tech changes sensor Same code Did a test on engine . Manual pressure gage read 40-50 psi! Good Engine idels 600 rpm Fault code comes up Pressure on smart craft reads 0.00 oil pressure 600 rpm, or 69.6 psi (on any other rpm ) Darin

      Started by:  Darin Chung in: General Discussion


      3 Replies
      August 16, 2019 at 8:32 am Greetings! I am having the same issue with my QSC 8.3. New sensor being flown in today in my remote location (Shearwater, BC), but based on your post, I have low confidence in that being the solution. Any help would be appreciated!

      Last Post by:  tombuskirk posted: 2 days ago

    • Engine flush fittings.

      This topic has 0 replies, has 1 voices, and was last updated by john 2 days ago

      August 16, 2019 at 8:10 am I see Seaboard has bronze in line flush fittings for cummins engines. Is there any more sizes available? I’m looking for different barb end sizes. I have a few boats I work on that I would really like to add the ability to flush easier. Most of the boats are live aboards. 1 1/4 ,1 1/2 1 inch. I probably can cobble something together but those bronze fittings are real nice.

      Started by:  john in: General Discussion


      0 Replies - Can you Help? ...be the First to Respond!

    • A thought about After Coolers

      This topic has 1 reply, has 2 voices, and was last updated by Tony Athens 2 days ago

      August 15, 2019 at 11:36 am I am new to engines with aftercoolers as my previous diesels were either naturally aspirated or simply turbocharged. After reading Tony’s Tips on aftercooler design/faults/maintenance I had a thought I would like to put forward. For a few years now I have coated the inside of my generator’s heat exchanger end caps and portions of the riser with Belzona epoxy products. I also perform Fresh water and SaltAway flushing whenever the …

      Started by:  pwrobert in: Cummins Marine Engines


      1 Reply
      August 15, 2019 at 6:39 pm IMO, the method you propose to decrease corrosion in the areas of the Cummins designed cooler would not be applicable unless you were to increase the ID of the first inch of end depth of the casting about 1/8″, then coat the machined surface with ????? (your “last forever” secret sauce) to bring the ID back to about 4.940″, and then re-machine again accurately to 5.000 +/- .010″………………

      Last Post by:  Tony Athens posted: 2 days ago

    • Qsb plug size in water pump (freshwater flush)

      This topic has 1 reply, has 2 voices, and was last updated by Tony Athens 2 days ago

      August 13, 2019 at 6:06 pm I am setting up fwf system for a friend. I did mine but don’t recall the plug size on the water pump. We will be going in after the impeller so he can flush without the engine running. I verified today he has his exhaust set up properly. Mikelson 43. Thanks. Mike

      Started by:  Mike Mason in: Cummins Marine Engines


      1 Reply
      August 15, 2019 at 6:22 pm Upper and lower test ports on the seawater pump 1/4″ NPT Tony Tony Athens Seaboard Founder Go here for the latest stuff we put together and share for all to see: https://www.sbmar.com/tonys-tips/

      Last Post by:  Tony Athens posted: 2 days ago

    • qsm 11 long term

      This topic has 1 reply, has 2 voices, and was last updated by Tony Athens 3 days ago

      August 14, 2019 at 2:22 pm I have a MIKelson Nomad with QSM11s .We run @1200-1300 rpm 95% of the time . which is 5 gal/hr and 91/2 -10 kts. Does it hurt to run this way most of the time? Should I run higher from time to time? It is a displacement hull so more rpms does not yield much more speed, thanks Joe Our Time

      Started by:  joe seaverns in: Cummins Marine Engines


      1 Reply
      August 14, 2019 at 8:41 pm The answer is in the link below and it has not changed, although it should be updated to say “as the the max HP per liter has gone up quite a bit since I wrote this with the new electronic engines , IMO, low speed running to add longevity to an engines life is even more advantageous” -Trust me, your QSM11’s love it…————- Seeing 30,000 + hours over a 10 year year period on QSL9s & QSB 5.9…

      Last Post by:  Tony Athens posted: 3 days ago

    • ZF tranny dipstick

      This topic has 1 reply, has 2 voices, and was last updated by Rob Schepis 3 days ago

      August 14, 2019 at 7:11 am On a ZF 80-1a transmission, what volume of fluid is represented between the low mark and high mark on the dipstick? In other words, if it’s on the low mark, how much fluid is needed to reach the high mark? Thanks WSBeach

      Started by:  John Larson in: Marine Transmissions


      1 Reply
      August 14, 2019 at 2:05 pm Don’t know if you can get a 100% solid answer on this other than measuring it yourself by starting at the low mark and noting what it takes to reach the high mark. FYI – not recommended to run engine oil or gear oil/fluid at high marks considering the potential for pitch and roll. Rob "Luck is the residue of good design."

      Last Post by:  Rob Schepis posted: 3 days ago

    • Fuel Sending Unit

      This topic has 1 reply, has 2 voices, and was last updated by Rob Schepis 3 days ago

      August 14, 2019 at 9:09 am Have a pair of 450 Diamond series engines in our 1998 Tiara 3500 Express. Both gas tanks replaced with new sending units matched to the VDO fuel gauges. Both tanks 175 gallon capacity. Ran out of gas on port side engine, even though fuel gauge showed little over 1/4 tank. Generator is off port side as well. Starboard side showed little less than 1/2 tank. Added 10 gallons to port side tank to get to fuel pumps. Port side tank fills up with 108 g…

      Started by:  Jim Gabilanes in: Instrumentation & Electronics


      1 Reply
      August 14, 2019 at 2:00 pm Sounds like you should have had adequate usable fuel – I would pull the tanks pick up tubes and inspect them. Rob "Luck is the residue of good design."

      Last Post by:  Rob Schepis posted: 3 days ago

    • Please evaluate my exhaust system

      This topic has 4 replies, has 2 voices, and was last updated by Charles A. Beever III 4 days ago

      August 12, 2019 at 1:23 pm Recent repower- older 250hp 6bta in a 236 Mako inboard. Engine was a spare irrigation unit in storage. Little to no use from what I was told. I just acquired the boat and love it. I realize I need to upgrade cooling system tank and plumbing away from the old “corner mounted tank” system. Main question here is do I need a riser? I’m not comfortable killing engine while out fishing due to possible backflow to turbo. Turbo has some broken b…

      Started by:  Charles A. Beever III in: Cummins Marine Engines


      4 Replies
      August 13, 2019 at 7:30 pm That would be getting close to strainer setup. I saw a circular setup on one of your writeups that angled fore and up and circled back. Seemed doable. I’m not saying crossover wouldn’t work. Just trying to apply KISS philosophy. Charles

      Last Post by:  Charles A. Beever III posted: 4 days ago

Viewing 20 topics - 1 through 20 (of 1,679 total)