Cummins Marine Diesel Repower Specialists Forums Cummins Marine Engines

Viewing 20 topics - 1 through 20 (of 3,703 total)
    • Cummins Marine Forum Topics
    • Zeus Pods: Good, Bad, Ugly??

      This topic has 10 replies, has 7 voices, and was last updated byMark Rinker 8 hours ago

      October 14, 2018 at 10:15 pm I am considering buying a Meridian 441 flybridge ‘motor yacht’, which is 47’ LOA and 31,000lbs. These come with various engine configurations but commonly, with QSB 425’s which can be either shaft-drive or Zeus pods. All my personal experience to date is with 6BTA 370’s in a conventional shaft drive arrangement. I am after some of Seaboard’s famous frank and honest advice: should I run away from pod drives….or go for them if they have a so…

      Started by: Paul Greenhalgh


      10 Replies
      March 18, 2024 at 1:07 pm Lots of helpful information found here Mercruiser Zeus Pod Owners Group   The most important upgrade for Cummins QSB / Zeus owners is the Seaboard Marine water pumps and impellers!!!    Keeps the temperatures down and extends the life of the steering seals.    Cool water flow is key!

      Last Post by: Mark Rinker posted: 8 hours ago

    • QSC 8.3 No Raw Water Circulation

      This topic has 6 replies, has 4 voices, and was last updated byBobby Harvey 8 hours ago

      March 17, 2024 at 3:26 pm I had the boat out 0f the water for maintenance for about 2 months. Installed new raw water pumps, hoses, seacocks, strainers. (New bilge). When I tried to start one of the engines, I couldn’t get water to circulate (out of the exhaust). Water is getting to the pump and to the fuel oil cooler ok but no water beyond that. It was working fine before this. I tried priming the system with water first from the heat exchanger to mitigate possibl…

      Started by: Bobby Harvey


      6 Replies
      March 18, 2024 at 12:57 pm Thanks Clark. All your suggestions are a possibility at this point. Strainer is primed and so is the intake hose and pump. I was able to detect a small amount of air through the fresh water flushing cap valve when I opened it while I had it running for a few seconds.  The o/f cooler is plugged, or at least restricting the water flow probably enough to cause this problem, and the O ring seat for the Stainless Tube to the o/f cooler is badly corro…

      Last Post by: Bobby Harvey posted: 8 hours ago

    • 4BT cam / crank

      This topic has 6 replies, has 2 voices, and was last updated byTony Athens 1 day ago

      March 16, 2024 at 11:53 am I have an engine that I am getting prepared to rebuild.  The cam part number does not match the part number in the parts manual for CPL 741. I did some research for a supersession part, but apparently the part number that the manual shows is the newest part number.  From my research the cam in CPL 741 is 392039 and that replaced 3925582′.  The cam in my engine has a strange part number, but it comes up on a search.  The cam I removed from …

      Started by: Shannon Ritzert


      6 Replies
      March 17, 2024 at 4:35 pm Reasonable?  IMO no , will it work –Not a  clue The 741 is a turbo charged engine and by design is lower compression.       2. The CPL 741 CAV pump is calibrated to for 150 HP/2800 RPM        3. The CPL 591 is a 65 +/- HP engine with higher compression, no turbo The engines have different injectors, etc etc etc. So , what are you trying to build?  a 4BT of a 4B?  Or , are you just trying to make a  engine start & run ?

      Last Post by: Tony Athens posted: 1 day ago

    • QSC approaching 5000 hours, major maintenance?

      This topic has 2 replies, has 2 voices, and was last updated byAndre Huizing 1 day ago

      March 17, 2024 at 2:20 am Hello experts, Our QSC8.3 490hp 2006 vintage just passed 4000 hours and I hear some people saying that 5000 hours is some “milestone” when major maintenance should be in order? I know Cummins is prescribing a valve adjustment at 5000 hours (which seems a huge amount to me for this but who am I to judge). Some info on our installation: single engined full displacement trawler; semi live aboards, engine runs regularly most of the year…

      Started by: Andre Huizing


      2 Replies
      March 17, 2024 at 9:17 am Thanks for the tips Tony. Most is still original except for the seawater pump and engine mounts (both replaced this year). As said we run >95% of time around 1300 rpm which in our case is 3 – 4 GPH. I keep an eye on the belt (approx. 3 yo). Seems fine but creates quite a bit of dust. We have conventional shaft drive through TwinDisc MG5091SC transmission. No ZEUS. Cheers, André

      Last Post by: Andre Huizing posted: 1 day ago

    • 6BTA5.9M3 1998 Barry engine mount issues

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

      March 14, 2024 at 7:34 pm I am a 2 year owner of a Little Harbor Whisper Jet 38 with the 370 hp 6BTA5.9M3 hooked up to Hamilton 273 jets via a Borg warner velvet drive  Model # 10-18-002– I have replaced a couple of the engine vibration mounts with those installed upon purchase identified as follow — Barry 27655-1 Cummins  3349229.  The engines run very smooth but there are a few mounts (including the new ones) with gaps between the rubber and metal casing of…

      Started by: David Foster


      1 Reply
      March 15, 2024 at 5:32 am No crystal balls here.. POST good PICTURES of what you see

      Last Post by: Tony Athens posted: 3 days ago

    • QSC 8.3 Coupling Bolts

      This topic has 8 replies, has 5 voices, and was last updated byBobby Harvey 4 days ago

      March 6, 2024 at 11:04 am Hi everybody! I have a QSC 8.3 500 HO driving a ZF 305 3A transmission. I’m trying to find 12 couplings bolts (and nuts). 5/8″ fine thread (18) x 2″ long – 12 point “extra hard”. Impossible to find (on this planet). Any help locating these would be appreciated. Thanks everyone! Bobby    

      Started by: Bobby Harvey


      8 Replies
      March 14, 2024 at 6:28 pm Thanks Gene. Very helpful information. I will go with this.   

      Last Post by: Bobby Harvey posted: 4 days ago

    • need to bond a t insalled for fresh water flush

      This topic has 3 replies, has 4 voices, and was last updated byPatrick Mangum 4 days ago

      February 5, 2024 at 12:40 am I am thinking of buying the fresh water t and plumbing to the back of the boat. The question cane up regarding bonding the T. I dont see a stud on the T. is it needed and if so any ideas to install a bonding wire. Thanks Rod

      Started by: rod robbins


      3 Replies
      March 14, 2024 at 6:13 pm Speaking of the T fitting – I have removed the fuel coolers. Would that section of hose between the outlet of the RW pump and bottom of the aftercooler be a good place to “T” into for FW flushing?   I only have external strainers

      Last Post by: Patrick Mangum posted: 4 days ago

    • Air in fuel lines

      This topic has 1 reply, has 2 voices, and was last updated byClark Leighs 4 days ago

      March 13, 2024 at 4:01 am I recently started catching air in my fuel system.  All component of the fuel system are less than five years old (tanks, lines, valves,etc)  The Racors were not catching air but the secondary filter on the engine was.  The fuel filter would be down quite a bit on the secondary.  To try to narrow things down I bypassed the secondary, changed the primary to a small micron, and ran the motor.  I don’t seem to be getting air anymore.  My thro…

      Started by: Mike Vinci


      1 Reply
      March 14, 2024 at 2:20 pm Check the filter seals between the filter body and the filter element.    THey should be replaced each and every time you change filters.   THey can harden a bit or take an impression from their metal contacts and unless you line those up perfectly they will will improperly seal next time.  Of course the filter element must be tightened properly or maybe the seal will fail to seal fully. I don’t mean cranking the daylights out of it but a …

      Last Post by: Clark Leighs posted: 4 days ago

    • 12v or 24v Alternator For QSC 8.3L with a 24V starter bank

      This topic has 5 replies, has 5 voices, and was last updated byGene Fuller 4 days ago

      March 9, 2024 at 3:23 pm New to forum. Hope this question falls within the bounds. Have recently acquired a Nordic 44 with a 24v starter battery bank (two 12s in series) for a 600 HP, Cummins QSC 8.3L.  Recently, had an alternator failure while on a trip.  Replacement alternator (that a dockside mechanic put it in) was labelled 12V.  Was this an error?  Don’t I need a 24V alternator to charge my battery bank?     Thanks,   Michae

      Started by: Michael Cunningham


      5 Replies
      March 14, 2024 at 6:51 am The standard configuration for the Nordic Tug 44 has been 100% 24 volt since its inception about 10 years ago. (Update from the previous Nordic Tug 42). Of course these are highly custom boats so anything is possible. However, it is very likely to be a completely 24 volt system, including all engine and battery related items as well as lighting, appliances, etc.

      Last Post by: Gene Fuller posted: 4 days ago

    • Cummins 6BTA 5.9 M3 engines. Raw Water Pump

      This topic has 2 replies, has 2 voices, and was last updated bybobandjoank 5 days ago

      March 12, 2024 at 12:21 pm Good morning, Seaboard Marine, I have twin Cummins 6BTA 5.9 M3 engines. (B5.9 M330, Cummins 330 HP M10TA). Their build date is February 2004 and would have been installed into my boat (Alaska 45 sedan cruiser, semi displacement vessel, privately owned used as a pleasure vessel), when built in 2004/5. Their serial numbers are Port 46368002 and Starboard 46371833. Current engine hours are approximately 2200 each. In July 2018 I purchased two SMX-1…

      Started by: bobandjoank


      2 Replies
      March 13, 2024 at 12:34 pm Thanks, Richard for your experience. I’m fully aware of the Nordic Tug 37; a good friend of mine has one which I think is the only Nordic Tug in Australia. He’s still perservering with the Sherwood pump despite my advice to change to a SMX. Knowing your boat gives me a lot of confidence in your reponse; many thanks, Bob

      Last Post by: bobandjoank posted: 5 days ago

    • Air in fuel lines

      This topic has 0 replies, has 1 voices, and was last updated by 5 days ago

      March 13, 2024 at 4:01 am I recently started catching air in my fuel system.  All component of the fuel system are less than five years old (tanks, lines, valves,etc)  The Racors were not catching air but the secondary filter on the engine was.  The fuel filter would be down quite a bit on the secondary.  To try to narrow things down I bypassed the secondary, changed the primary to a small micron, and ran the motor.  I don’t seem to be getting air anymore.  My thro…

      Started by: Mike Vinci


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

    • CPL 8464 to CPL8732

      This topic has 2 replies, has 2 voices, and was last updated byngonev 1 week ago

      March 9, 2024 at 1:11 pm Hello, I just purchased a new to me boat with two qsb 380’s I have read all the info on loading the engines with the correct prop. At sea trial with 1/4 tank and 4 adults the engines spun to about 3k rpm. For my own curiosity, I looked into converting qsb 380hp to 425hp. I see that the 425 has slightly larger injectors and flows a couple of gallons more raw water.  Insite tells me that the heads are different.  1) what will be the outcome if onl…

      Started by: ngonev


      2 Replies
      March 10, 2024 at 8:23 am Thank You Tony for the quick response!  I will bring the boat home in about a month and follow your way to check if the boat is properly propped. <br /><br />

      Last Post by: ngonev posted: 1 week ago

    • Help identifying 6cta hp or cpl

      This topic has 2 replies, has 2 voices, and was last updated byShawn 1 week ago

      March 9, 2024 at 12:24 pm It has the older nippon denso pump. Trying to figure out how to post a picture with my phone…   Tag is lost. 

      Started by: Shawn


      2 Replies
      March 9, 2024 at 4:56 pm Rebuild parts, dropped a valve 

      Last Post by: Shawn posted: 1 week ago

    • QSC exhaust flange

      This topic has 3 replies, has 2 voices, and was last updated byTony Athens 1 week ago

      March 9, 2024 at 1:59 pm I’m looking to the name or part number for the attached flange.  It has 6 broken bolts,and i may be better just replacing    Thanks      

      Started by: pm


      3 Replies
      March 9, 2024 at 3:06 pm The flange on your mixer will bolt directly to the turbo without that intermediate adapter flange. It all just needs to cleaned up properly and use the proper hardware and graphite gaskets

      Last Post by: Tony Athens posted: 1 week ago

    • Correct cummins paint 1 2

      This topic has 26 replies, has 14 voices, and was last updated byTony Athens 1 week ago

      January 1, 2017 at 9:05 pm for a cummins QSC8.3-540 with a CPL8017 is the correct cummins white paint part number 3885912?  

      Started by: Philip


      26 Replies
      March 9, 2024 at 9:51 am My long term Rattle Can Experience.   1–Heating the can in hot water to 100-140F makes for a superior spray experience– 2– you cannot over shake 3–keep some real lacquer thinner in a baby food jar–Soak your spray tips in it and then blow them backwards to clean them using an air nozzle   Hope this helps the frustration level some

      Last Post by: Tony Athens posted: 1 week ago

    • Ordering new JWAC, no need for new air crossover inlet, correct?

      This topic has 4 replies, has 2 voices, and was last updated byTony Athens 1 week ago

      February 4, 2024 at 4:16 pm Hello, I’ll be ordering a new JWAC for my 6BTA5.9 later this week. Using quick serve I cross referenced to find your correct part number.  I had my old one cleaned at a reputable shop in my area that specializes in heat exchangers, Aftercoolers etc, and even though they said it was cleaned and clear and supposedly tested, it is plugged.  Whole other story but that caused many issues and delays with diagnosing rough running, because “the after co…

      Started by: Mark


      4 Replies
      March 8, 2024 at 4:45 pm Send those pics to  [email protected]  Put your same question in the email. He’ll ask me to look into it.

      Last Post by: Tony Athens posted: 1 week ago

    • 6CTA Tach Sensor Replacement

      This topic has 1 reply, has 2 voices, and was last updated byTony Athens 1 week ago

      March 7, 2024 at 5:13 am Since I had my aftercoolers off for servicing, I decided to replace the flaky tach sensor(s) which were making my Tach’s bounce.    I thought this was going to be a quick task. Well, aluminum sensor into steel housing.   The sensor broke off right in the housing.   After pulling out all the copper wire it was essentially a broken off pipe in the housing.  I tried all kinds of easy outs, etc.  Didn’t budge. After drilling it out succe…

      Started by: Eric Fontana


      1 Reply
      March 8, 2024 at 4:40 pm No fun job at all but you persevered..  Hope you installed the new unit with plenty of grease

      Last Post by: Tony Athens posted: 1 week ago

    • Aneriod Adjustment?

      This topic has 11 replies, has 5 voices, and was last updated byTony Athens 1 week ago

      February 27, 2024 at 7:05 am I have a pair of ’99 6CTA’s with 2,400 hours.  I’ve owned the boat for 13 years and these engines have been great.  But, on takeoff, the srtb engine shows some black smoke and needs a little more throttle than port to get the turbo to kick in.  It has always done this.  Once on plane, all good.  Just when getting on plane does this happen. I remember a “lazy Aneroid” discussion here, and thought this might be the ca…

      Started by: lpmcc


      11 Replies
      March 8, 2024 at 4:26 pm Basically the aneroid limits the fuel to limit or control excessive black smoke in relation to boost pressure, especially during acceleration..  If you have black smoke you typically do not have an aneroid iuse.. If the engine engine will not accelerate or lags,  and you have dark smoke, it’s usually related to too much prop and the operator is in denial...    Do your 6CTA’s reach an accurate 2700 RPM under fully loaded vessel c…

      Last Post by: Tony Athens posted: 1 week ago

    • Cummins Heat Exchanger University Project

      This topic has 1 reply, has 2 voices, and was last updated byRob Schepis 1 week ago

      March 8, 2024 at 5:26 am Hi everyone. I am a 4<sup>th</sup> year student studying Mechanical Engineering at Heriot-Watt University, Edinburgh, Scotland where I am conducting a project. The project focuses on the problems that shell and tube heat exchangers face when using seawater as the cooling fluid such as fouling and corrosion and how over time this affects the overall heat transfer between the fluids.    I am experimenting with a fouled Sen-Dure shell a…

      Started by: Robert MacLean Smith


      1 Reply
      March 8, 2024 at 7:57 am See attached for the Sherwood 17000 on on the  coolant pump.

      Last Post by: Rob Schepis posted: 1 week ago

    • CT6A-8.3 480 Antifreeze bled

      This topic has 1 reply, has 2 voices, and was last updated byJohn 1 week ago

      March 6, 2024 at 4:16 pm After draining the antifreeze out of my CT6A 8.3 480, I had a gallon left over. Is there a bled somewhere that will bled the trapped air?

      Started by: Richard Dodson


      1 Reply
      March 6, 2024 at 7:31 pm If no one else chimes in maybe there is a bleed but I’d just run it a bit and let the system work the coolant through engine and then after it cools down, just top up.   You’ll find the extra gallon that way I’d bet. Good luck

      Last Post by: John posted: 1 week ago

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