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Viewing 20 topics - 1 through 20 (of 1,185 total)
    • Cummins Marine Forum Topics
    • WOT RPM speed to weight relationship.

      This topic has 11 replies, has 4 voices, and was last updated by Tony Athens 1 hour ago

      December 10, 2018 at 12:05 pm Hi all, Reading various topics I’m still trying to understand how WOT RPM is affected by weight. On my boat it seems that I remember and I do need to recheck it again, that my WOT was not affected much if at all by weight. However my speed did decrease. Taking a planning Hull boat with clean bottom propped correctly would a lighter boat have a higher WOT RPM than a heavy boat or will the boat just go faster than a heavy boat with the WOT rpm s…

      Started by:  Joe Monaco in: General Discussion


      11 Replies
      December 14, 2018 at 4:30 pm How about this to some it up.. Propping a boat on paper, especially one that goes from hull speed to planing speed with speeds that are in-between is one on the true Grey Sciences.. Not much different than the torsional vibration (TVA’s) stuff I box with Cummins just about every month on new engine installs—IMO, another Grey Science for the couch engineers that like to run numbers, numbers, and then more numbers.. The problem with the TVA…

      Last Post by:  Tony Athens posted: 1 hour ago

    • Motor eléctrico mal funcionamiento

      This topic has 4 replies, has 2 voices, and was last updated by Javier 1 hour ago

      December 13, 2018 at 3:58 pm Hola de nuevo, desde hace un par de semanas el motor de estribor cuando enciendo el contacto se pone en funcionamiento algún motor eléctrico, pienso puede ser la bomba de combustible, que hace muy mal ruido,como si se engarrotara, pero después deja de sonar y el motor no da ningún fallo,funciona todo bien.Que puede ser?. Gracias

      Started by:  Javier in: Cummins Marine Engines


      4 Replies
      December 14, 2018 at 4:20 pm Gracias Rob, lo observaré.

      Last Post by:  Javier posted: 1 hour ago

    • Removing aftercooler core 1 2

      This topic has 39 replies, has 7 voices, and was last updated by Rob Schepis 2 hours ago

      December 1, 2018 at 5:35 pm Trying to remove aftercooler core on a 6cta. I’ve used penetrating oil and wd40, but can’t make it budge. Do I just pour wd40 in the center ports and let it soak from the inside? Thanks, Scott

      Started by:  MATTHEW SCOTT WARD in: Cummins Marine Engines


      39 Replies
      December 14, 2018 at 3:29 pm If the housing is on it’s last leg so to speak maybe give this product a try? https://repaintsupply.com/usc-14010-all-metal-polyester-aluminum-filler-p1073.html Rob "Luck is the residue of good design."

      Last Post by:  Rob Schepis posted: 2 hours ago

    • 6 BTA 250 HP Performance

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

      December 14, 2018 at 11:55 am General question here… My boat is a 31 North Coast Express, twin Cummins 6 BTA Recons with around 800 hours. The boat cruises around 17 knots at 2100 RPMS, wide open i’m around 20 knots at 2400 RPMs. I would love some ideas to increase the horse power and get the boat cruising around 20 plus knots. JC

      Started by:  Jamie carusone in: Cummins Marine Engines


      1 Reply
      December 14, 2018 at 3:19 pm Jamie carusone wrote: wide open i’m around 20 knots at 2400 RPMs That’s a 2,600rpm rated engine?? ……Got a serial number? Rob "Luck is the residue of good design."

      Last Post by:  Rob Schepis posted: 2 hours ago

    • SMX water pump impeller change

      This topic has 7 replies, has 4 voices, and was last updated by Rob Schepis 2 hours ago

      December 13, 2018 at 11:23 am I am attempting to replace the impeller from my SMX pump. I installed it 3 years ago and in order to remove the old Sherwood pump I had to remove the motor mount. As you can see the impeller can only come out 3/4 of the way due to the fuel hose that comes off of the fuel filter and goes to the injection pump? (Bosch). I need to remove this hose to finish and it appears it would be easiest to remove the banjo fitting at the pump. (second picture …

      Started by:  Kevin Carlson in: Cummins Marine Engines


      7 Replies
      December 14, 2018 at 3:07 pm Not sure I am agreeing with the logic there — you’d rather remove & reinstall a fuel line in a tight space than try harder to R&R the impeller ? From that pic you should have the room you need, just flex the fuel line towards the engine a bit and pull the impeller out to the side and around the fuel line. It should come.. And then just lube the pump bore and new impeller to aid in the reinstall (and priming). Rob "Luck is …

      Last Post by:  Rob Schepis posted: 2 hours ago

    • Broken Throttle because of misalignment

      This topic has 6 replies, has 2 voices, and was last updated by Tony Athens 11 hours ago

      December 11, 2018 at 4:36 pm The broken throttle that was overtightened is also misaligned. The new cable was attached by a bolt and locknut. This placed the cable in a bind because of the angles. Any suggestions for a proper repair? The throttle is ordered from you and is properly installed. I need help with attaching the cable with correct hardware. Thanks, Retired Diesel Instructor 3782 Blueberry Ln St James City Florida 33956 Attachments:You must be logged in to access…

      Started by:  Sonny Jim Reeves in: Cummins Marine Engines


      6 Replies
      December 14, 2018 at 5:50 am Corey left room for improvement.. I’ll get him to change the page. 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/ Attachments:You must be logged in to access attached files.

      Last Post by:  Tony Athens posted: 11 hours ago

    • Solenoid troubleshooting

      This topic has 1 reply, has 2 voices, and was last updated by Corey Schmidt 1 day ago

      December 12, 2018 at 3:33 pm I read the article on fuel solenoid troubleshooting, and there are a couple things that aren’t clear to me: 1) It says to move the solenoid fuel arm to the top and then zip tie it for the test. So, does that mean you zip tie it when the engine’s off… then start it up and the engine will function normally from idle all the way to WOT? I guess what I’m looking for is confirmation that the fully retracted/zip tied arm posi…

      Started by:  Mike Schmidt in: Cummins Marine Engines


      1 Reply
      December 13, 2018 at 12:01 pm Mike, yes the fuel solenoid manages the travel of the fuel lever (which allows fuel to pass through into the pump). If you zip tie the lever in the fully UP position, you will be able to start and run the engine from idle through WOT. Only way to stop the engine at that point is to cut the zip tie, obviously. If the solenoid is not lifting the lever to full open, odds are either its corroded or just DONE. Either way it will probably need to be r…

      Last Post by:  Corey Schmidt posted: 1 day ago

    • Benefits of Freshwater Flushing

      This topic has 13 replies, has 7 voices, and was last updated by Mike Schmidt 1 day ago

      October 27, 2018 at 2:02 pm In the last while, there has been some discussion on the forum where the benefits of freshwater flushing have been debated. I am no expert and often seek help from the contributors here, but now, I am a big believer in freshwater flushing. This fall, I have undertaken some maintenance on my engine, including replacing the idler pulley, refurbishing the alternator, removing the fuel cooler, and doing the aftercooler. It has been 2 full summer cru…

      Started by:  firehoser75 in: Cummins Marine Engines


      13 Replies
      December 13, 2018 at 9:22 am Tony Athens wrote: Mike, If your exhaust in “inherently safe” as to water flow to the exhaust exit into the ocean, then you would not even have to start the engine to do it this way or shut the seacock if hooked up the the OUTPUT port on the pump.. Let’s “see’ what you have between the MIXER and the exhaust exit. Pics and an elevation sketch in relation to the LWL sitting at the dock. Tony Well, I have a lift muffler so I’ll hav…

      Last Post by:  Mike Schmidt posted: 1 day ago

    • To FASS or not to FASS

      This topic has 5 replies, has 5 voices, and was last updated by dave.higby 2 days ago

      December 10, 2018 at 11:40 am A number of my fellow Selene owners have installed so-called “FASS” (trademark) fuel filtration systems to address a problem with lift pump failures on their single Cummins QSB 5.9 diesels. The FASS system has it’s own lift pump, with a particulate/water filter as well as an air separator. The popular configuration involves installing the FASS system upstream of the fuel distribution manifold and the primary fuel filters, whi…

      Started by:  dave.higby in: Cummins Marine Engines


      5 Replies
      December 12, 2018 at 4:07 pm Thanks for your reply Tony. I spoke to Brendan and Justin yesterday and they were extremely helpful. Based on advice from Brendan, I am going to go ahead and proactively replace my lift/priming pump since it is the original 2006 version. I am also looking hard at your double double quantum kit. I’m challenged for space in my engine room and am wondering if there is any point in retaining the existing dual Racor filters (in series with …

      Last Post by:  dave.higby posted: 2 days ago

    • Over-oiled Airsep

      This topic has 5 replies, has 4 voices, and was last updated by Philip 2 days ago

      December 11, 2018 at 10:20 am I over-oiled my Walker Airseps last summer, as I discovered a bunch of the red oil dripping out of the filters after I installed them. The dripping subsided after a week or so. Well, my new problem is that my port (6bta) engine is not making WOT (~200rpm shy of previous WOT). I’m in the process of going through all of Tony’s recommendations on his tips page, but I was wondering if an over-oiled air filter could contribute to this?…

      Started by:  Mike Schmidt in: Cummins Marine Engines


      5 Replies
      December 12, 2018 at 3:14 pm You could pressure test the entire assembly. Matter of fact I like to do that post assembly every time to ensure a good seal. Just block off one end of the water inlet/outlet and block the other end with a pressure gauge/schrader fitting. Pump air into the fitting, 15-20#’s should be plenty and let it sit overnight….

      Last Post by:  Philip posted: 2 days ago

    • Sizing Fuel Line for Pressure Drop

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

      December 12, 2018 at 2:09 pm On the SB Marine website, Tony has a pressure drop article which results in a pressure drop of .4” HG for a 20 foot run of ½ inch fuel line. I am coming up with the same number, roughly. My boat is very similar to the example, ie about 20 feet, new build, Cummins 325 HP, 32 foot Holland. I don’t understand why I should increase to 5/8 line over 15 feet per the article. If I am changing fuel filters at 10” HG, it is such a small fractio…

      Started by:  Eric Johnson in: Cummins Marine Engines


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

    • Aftercooler O-Rings, thin or fat? How tell?

      This topic has 11 replies, has 4 voices, and was last updated by Corey Schmidt 3 days ago

      December 10, 2018 at 3:23 pm For a 5.9 B. Aftercoolers look same on each of my 2 engines. Port s/n 46027817 although this aftercooler was replaced with new 2 years ago Stbd s/n 60235940 Fat or thin? — each fit. I have each type. What am I looking for here? Mike

      Started by:  Michael Loy in: Cummins Marine Engines


      11 Replies
      December 11, 2018 at 11:04 am All good suggestions everyone… thanks! Corey Schmidt VP, Operations Seaboard Marine, Inc.

      Last Post by:  Corey Schmidt posted: 3 days ago

    • Oil Pressure Switch

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

      December 10, 2018 at 7:55 pm I have an alarm going off with Good temp and oil pressure. I disconnected the oil pressure switch and alarm does not sound. I have ordered the SMX switch from SBMAR. My question is how should I install the SMX Switch. It has a single pole. The switch I am removing has a clip and two wires going to it. I believe it is cummins part 3056344. Do I attach both wires to the single SMX pole or does one need to go to a short ground? Thx Cpt.Blai…

      Started by:  Blair Ostergren in: Cummins Marine Engines


      2 Replies
      December 10, 2018 at 8:49 pm No, do not attach both wires together. A single terminal switch is engine ground, aka case ground, with the one wire being a signal wire. A twin terminal switch is a floating ground which is a signal wire and a ground wire. Are you sure what you are replacing is a “switch” and not a “sending unit” ? Big difference. The Cummins OEM instrument cluster setup does not include a switch, just the sending unit and it is the…

      Last Post by:  Rob Schepis posted: 3 days ago

    • Block Heater – QSB 230 5.9

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

      December 10, 2018 at 1:34 pm Hi! Looking for some advice from the experts: I want to install an immersion style block heater to my QSB 230 5.9L (SN 46930753). On my boat, the cabin heat exchange seems to be plumbed to the Block Heater port. My assumption is that red circles should be heat exchange and yellow block heater? What is blue for?? This article confuses me a bit: https://www.sbmar.com/articles/heater-hookup-ports-for-your-b-c-series-cummins/ I think this article…

      Started by:  carrata in: Cummins Marine Engines


      2 Replies
      December 10, 2018 at 2:17 pm Thanks Philip, good suggestion. I will go with the pad. Next question is whether or not I should bother re-porting the heater hose. Any benefit, or leave it alone?

      Last Post by:  carrata posted: 4 days ago

    • Head Gasket Leak 6bta

      This topic has 1 reply, has 1 voices, and was last updated by Justin Murphy 4 days ago

      December 10, 2018 at 7:50 am I have a 370hp version of the 6bta, it has 130 hours, it was a factory rebuild installed a couple years ago. I recently had the head gasket replaced due to an overheat issue (raw water intake left closed). It got hot for just a minute and was shut down on alarm, but apparently that was enough to blow the gasket and bend the exhaust rod on number 4. Head was decked and 7/1000 removed, magnafluxed for leaks and new valve seats installed. I was …

      Started by:  Justin Murphy in: Cummins Marine Engines


      1 Reply
      December 10, 2018 at 1:35 pm As a follow up, maybe someone could confirm the right gasket was used? My serial number is 60260856, CPL is 8457. The part number that I found for .10 over is 328337, does this seem right? Not even sure that’s what he used, waiting to hear from him. My mechanic knows the 5.9 but don’t think he works much with the marine version, not sure if there is any difference with head gaskets here anyway? Cactus

      Last Post by:  Justin Murphy posted: 4 days ago

    • SMX1730 impeller replacement

      This topic has 5 replies, has 5 voices, and was last updated by Rob Schepis 4 days ago

      December 8, 2018 at 12:48 pm I have a pair of SMX1730 pumps I’m replacing the impellers in. The old impeller came out pretty easy, but I’m having trouble getting the new impeller in. Is there a secret to compressing the tabs enough to get them in the housing? Thanks, Scott

      Started by:  MATTHEW SCOTT WARD in: Cummins Marine Engines


      5 Replies
      December 10, 2018 at 7:24 am MATTHEW SCOTT WARD wrote: Thanks for the advice. Due to limited space, I’ll give the zip tie method a try. Thanks! Scott Try to take some pics while you’re at it and post them here. Always helpful to others.. Rob "Luck is the residue of good design."

      Last Post by:  Rob Schepis posted: 4 days ago

    • QSC Oil Leak

      This topic has 6 replies, has 4 voices, and was last updated by Tony Athens 1 week ago

      December 6, 2018 at 5:26 pm I have an oil leak on a QSC 500 where the drain hose from the air sep attaches to the oil pan. This looks to me like an oil drain fitting that was adapted for a hose but before I remove the fitting and reseal I wanted to make sure there is not a nut inside the pan. Thanks to all and love the site!

      Started by:  Dave Carlson in: Cummins Marine Engines


      6 Replies
      December 7, 2018 at 4:42 pm Just don’t get True Blue in your hair ! 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: 1 week ago

Viewing 20 topics - 1 through 20 (of 1,185 total)