Cummins Marine Diesel Repower Specialists Forums Recently created topics

Viewing 20 topics - 1 through 20 (of 5,072 total)
    • Cummins Marine Forum Topics
    • Constant Torque Hose Clamps

      This topic has 2 replies, has 3 voices, and was last updated byRob Schepis 10 hours ago

      March 27, 2024 at 9:14 am Curious if there is any specification or guidance on tightening these hose clamps.  My impression is that the spring needs to have some give both to tighten and loosen to allow expansion.   Anyone have any advice vs just tightening them ‘tight’ like normal hose clamps.

      Started by: Zac Schramm in: Cummins Marine Engines


      2 Replies
      March 27, 2024 at 6:41 pm I don’t think my method is more technical or scientific but I use a good nut-driver with a nice quality handle and make them basically as tight as I reasonably can with this limited tool.  No wrenches  and no ratchets.  Just “nut-driver tight”  The only time I’ll resort to a socket and extensions on a 1/4″ drive is if something is harder to get to and then I am careful to only make ’em good and snug with the 1…

      Last Post by: Rob Schepis posted: 10 hours ago

    • Cummins 4BTA 250 –Starboard engine WOT low/Power low

      This topic has 7 replies, has 3 voices, and was last updated byTony Athens 1 day ago

      March 26, 2024 at 4:01 pm Starboard engine not reaching WOT only hitting 2900, Port will make 3200rpm I’ve attached a spreadsheet with rpms, boost and egt values on both engines, please have a look. Testing was done with full load of fuel, water, 5 persons and Gear/food for a week.   Port engine 150hr/3year old major rebuild, runs great, little white smoke at startup, makes WOT 3200. Port engine WOT (3200) has steady even 30 PSI boost. Starboard engine 700 plus hou…

      Started by: boardsteez in: Cummins Marine Engines


      7 Replies
      March 27, 2024 at 5:21 am Have yopu gome thru the list in this article and not skipped anything? https://www.sbmar.com/featured-article/understanding-low-power-troubleshooting/    

      Last Post by: Tony Athens posted: 1 day ago

    • Cummins 6CTA8.3-M Heads

      This topic has 2 replies, has 3 voices, and was last updated byRichard Dodson 16 hours ago

      March 26, 2024 at 10:30 am I’m looking at purchasing a boat that has a pair of Cummins 6CTA8.3-M engines, CPL# 2960. At the very least I would follow the advice that is given here about propping the boat to the 450 fuel curve. My question is in regards to the heads. The engine SN’s are 46435824 and 46434682. Are these engines heads subject to the valve seat dropping out that I’ve been reading about or are they of a later vintage that I don’t need t…

      Started by: Curt Schultz in: Cummins Marine Engines


      2 Replies
      March 27, 2024 at 12:37 pm Hi, My ESN is below the TSB that Cummins issued in 2006 but above yours, you probably have the old heads.  The upgraded head # is: 4942463.  I had the misfortune of dropping an exhaust valve, around $22,000 to rebuild it. As a precaution, I swapped the head on the other side, around  $9,000. In addition I reduced the prop pitch 2″. This resulted in the desired 450 fuel burn to be 27.4 GPH at 2200 RPM which results in 18-19 Knots.   The sea…

      Last Post by: Richard Dodson posted: 16 hours ago

    • Hydraulic Second steering station question

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

      March 26, 2024 at 8:03 am Good Morning. I am adding a second steering station up in my tower. Ive plumbed all my hydraulics but I do not think I have them hooked up correctly. I am able to get the rudder to turn left and right but it feels like turning the bottom station with the boat off. it is very stiff. I am not sure in this diagram which station is suppose to be the 1st and second station.  my upper station is shown in a picture. The yellow tape line is tank, no tap…

      Started by: rick martinez in: Instrumentation & Electronics


      1 Reply
      March 26, 2024 at 6:16 pm You have orbitol power steering—————Before you added the second staion, was everything working right?  Did you make any other changes at the same time? Let’s get back where all worked right and figure all you did since then.    I want a clear pic of the original helm pump,  and the new one.      Look carefully at the drawing–are you hooked up exactly as shown between to two helm pumps ?

      Last Post by: Tony Athens posted: 1 day ago

    • down on speed

      This topic has 2 replies, has 3 voices, and was last updated byTony Athens 23 hours ago

      March 25, 2024 at 2:32 pm Hi all i have a 1999 Carver 530 with a pair of Cummins 6CTA 450HP engines and i am way down on speed. WOT is 2240RPMs and only delivers 16 knots … i have previously had it up to 22 knots… bottom of the boat is clean both engines have been rebuilt by Cummins… air filters all new… i am stumped on this tried trim tabs in all different positions with minimal affect… is there something i am missing..

      Started by: inmotion in: Cummins Marine Engines


      2 Replies
      March 27, 2024 at 5:24 am Like C;ark said, close to zero infor to work with.. Have you gone thru this article and not skipped anything ?–That would be the basic way to start. Understanding Low Power Troubleshooting        

      Last Post by: Tony Athens posted: 23 hours ago

    • ZF Hurth tag missing

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

      March 25, 2024 at 7:38 am If the tag is missing from my transmission, how would someone tell what model V-Drive I have.  It is bolted to the following spec Cummins.  Model: 6BTA5.9.M2 Serial:4483T453 HP: 300HP Is there a certain profile.  I ask because I need a new coupler and I want to make sure I order the correct model for my transmission.   The shaft size is 1.5″ I can post pictures later today. Thanks.~Mike

      Started by: FourWinnsMike in: Marine Transmissions


      2 Replies
      March 25, 2024 at 7:22 pm Yes, it does have ATF.  Thanks Rob!!!

      Last Post by: FourWinnsMike posted: 2 days ago

    • Fuel Flushing

      This topic has 1 reply, has 2 voices, and was last updated byRob Schepis 4 days ago

      March 23, 2024 at 8:26 pm Hi all, I am finishing up a bunch of work on cooling system maintenance on 2003 6BTA.  Doing the fuel cooler removal, combo block removal, replacing all fuel hoses.   I’m wondering what I do about flushing the new fuel hoses, specifically the one after the on-engine fuel filter.  It is quite long on remote filter. I was wondering if I could just take hose going into engine fuel pump and connect that through a 12v fuel pump and connect to r…

      Started by: Zac Schramm in: Cummins Marine Engines


      1 Reply
      March 24, 2024 at 5:02 am That would do it.

      Last Post by: Rob Schepis posted: 4 days ago

    • Dumb ass move

      This topic has 3 replies, has 3 voices, and was last updated byLew 3 days ago

      March 23, 2024 at 11:02 am Short story, just serviced port Heat exchanger and installed smx 160 thermostat. Was excited to try it all out before I serviced  the SB side. Went out of the harbor and watched sb side climb from like 180-210 when I put load on about 2200rpm.  I noticed white  smoke that I don’t usually have. “CRAP” immediately shut down and ran down stairs. Opened sea cock. Re started engine and temp fell quick and smoke gone…  Got back…

      Started by: Lew in: Cummins Marine Engines


      3 Replies
      March 24, 2024 at 9:22 am Copy that Rob,  the manifold looks fine, no coolant loss. What else would I look for? I am in process of servicing heat exchanger on this engine now and will also install a 160 smx thermostat. Thx for reply

      Last Post by: Lew posted: 3 days ago

    • Will the SMX QSB Seawater Pump fit my 1999 Cummins 6BTA5.9M3 engine

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

      March 23, 2024 at 5:39 am I have a 1999 Cummins 6BTA5.9M3 marine engine, ESN 45777183.  Will the SMX QST seawater pump fit that engine?  It is not 100% clear to me from the sbmar.com product description. SMX QSB Seawater Pump I am looking for a spare pump.  The Sherwood P1730C pump I recently installed experienced a cam screw fatigue failure after only 380 hours of use.  I see that the SMX QST seawater pump uses two of these screws, and although that should be better,…

      Started by: Mark Kiehl in: Cummins Marine Engines


      1 Reply
      March 24, 2024 at 6:50 am You CANNOT use a QSB pump on your mechanical engine –It’s made to be belt driven ALL SMX pumps have the double cam screw by original design besides other unique features that make it what it is.

      Last Post by: Tony Athens posted: 3 days ago

    • SmartCraft malfunction

      This topic has 4 replies, has 2 voices, and was last updated byBill Quinlan 2 days ago

      March 22, 2024 at 9:48 am I’ve had a problem with the electronics on my Cummins QSB5.9-330HO.   It began with loss of throttle. Local Cummins replaced module and Medusa harness. Subsequently, I have lost throttle twice. The same tech scratched his head but couldn’t fix. Later I went to the boat and it had fixed itself. The 24 to 12 volt has blown its fuse twice. Most recently, the entire electronic controls shut down. The fuse was replaced and all powered up again. Why i…

      Started by: Bill Quinlan in: Cummins Marine Engines


      4 Replies
      March 25, 2024 at 5:43 pm The starter is 24 volt. 

      Last Post by: Bill Quinlan posted: 2 days ago

    • 250hp Cummins Performance Options

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

      March 22, 2024 at 9:34 am Hello, Family friend reached out to me on increasing the performance of a pair 1988/89 of 250hp cummins marine (CAV pump). While my knowledge of building high powered cummins for the truck world is pretty extensive it isn’t necessarily a 1:1 translation to the marine world. They are looking to get 400hp out of each engine, and best I can tell from reading thru this forum is it is doable although at the price point to do it they would be be…

      Started by: Teddy in: Cummins Marine Engines


      2 Replies
      March 23, 2024 at 10:54 am Would be max 400hp, but certainly more than 250hp for cruising.

      Last Post by: Teddy posted: 4 days ago

    • Cummins 6BTA Aftercooler Core

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

      March 20, 2024 at 4:53 am 2 questions. My aftercooler core is bad. Does not hold pressure. Housing is fine. 1, does anyone know where I can get a used aftercooler core? 2, has anyone used a perkins core? any recommendation about using an aftermarket core vs a cummins?   Thanks, Jim

      Started by: James Hampton in: General Discussion


      1 Reply
      March 20, 2024 at 5:22 am Have you identified where the core leak is?  If it’s one or two tubes they can be plugged off.  As to used – eBay, FB marketplace, etc.  Don’t have any experience with any other cores other than Cummins and SMX.

      Last Post by: Rob Schepis posted: 1 week ago

    • 6BTA 370HP losing coolant with heavy white exhaust

      This topic has 13 replies, has 5 voices, and was last updated byKyle Routh 3 days ago

      March 19, 2024 at 4:13 pm Two mornings ago as I was performing my pre-run checks, I noticed the coolant overflow reservoir on my STBD main engine (SN:46174828) was empty.  I checked the main reservoir and it was completely filled.  So I started looking for external leaks but could find no evidence of an external leak anywhere.   I turned to looking for internal leaks and checked the oil and transmission fluid but neither had any abnormal level or visual indication o…

      Started by: Kyle Routh in: Cummins Marine Engines


      13 Replies
      March 24, 2024 at 9:53 am Thanks Francis & Rob, I am guilty as charged.  I do run the engines up to WOT for 10-15 mins occasionally, but not each run.  Probably once every week or so, which I’d estimate to be about once every 40-50 hours of run time.  I was better about it when we first bought the boat, but I have become complacent over time.  I’ll definitely be changing my practices.  I am not sure how they were taken care of before I got the boat and I …

      Last Post by: Kyle Routh posted: 3 days ago

    • 6CTA Starboard Aftercooler Recommendation

      This topic has 5 replies, has 4 voices, and was last updated byRichard Dodson 4 days ago

      March 19, 2024 at 11:10 am Good morning SBA team,  I pulled the starboard aftercooler for maintenance and discovered some corrosion. I have a pair of 2002 6CTA 450’s which were last serviced in 2019 and installed fresh water strainer caps at the same time. I was surprised at the amount of salt build up, I religiously flush the engines after every use except when cruising multiple days which is only  about 10-12 days a year. There was quite the buildup in the hose ex…

      Started by: Harold in: General Discussion


      5 Replies
      March 23, 2024 at 5:30 am Just curious, how long are you running the engines with the fresh water hooked up and are you leaving the seacock open or closed?

      Last Post by: Richard Dodson posted: 4 days ago

    • QSC 8.3 No Raw Water Circulation

      This topic has 10 replies, has 5 voices, and was last updated byBobby Harvey 2 days 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 in: Cummins Marine Engines


      10 Replies
      March 25, 2024 at 2:40 pm I am in the process of replacing both Aftercoolers. The old ones have never been serviced. Crushed them both trying to press them out of the housing. Able to save one housing. The port Gear Oil/Fuel cooler was plugged up. Hopefully that was the water circulation problem. I’ll find out when I get it back together. Both Gear Oil Fuel Coolers tested good. 100%. So, I can re-use them. I’m waiting on Seaboard to ship me the new Aftercoole…

      Last Post by: Bobby Harvey posted: 2 days ago

    • QSC approaching 5000 hours, major maintenance?

      This topic has 2 replies, has 2 voices, and was last updated byAndre Huizing 1 week 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 in: Cummins Marine Engines


      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 week ago

    • 4BT cam / crank

      This topic has 7 replies, has 2 voices, and was last updated byShannon Ritzert 1 week 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 in: Cummins Marine Engines


      7 Replies
      March 19, 2024 at 9:21 am my 150hp 4bt overheated, so I am trying to save money on a rebuilding it.  I purchased the 65hp 4b a long time ago for a parts engine.  When I purchased it, I did not realize the differences between the engines.  When I disassembled the 4b, I seen that this engine has almost no time on it.  I am cross referencing the parts of the 4b to use on the 4bt rebuild.  I figure that any part that has less time on it, I will use for my rebuild. The block …

      Last Post by: Shannon Ritzert posted: 1 week ago

    • 6BTA5.9M3 1998 Barry engine mount issues

      This topic has 1 reply, has 2 voices, and was last updated byTony Athens 1 week 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 in: Cummins Marine Engines


      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: 1 week ago

    • Engine serial number location

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

      March 14, 2024 at 10:11 am Hello, Can someone tell me where I can locate the serial numbers on my Cummins QSB 5.9’s. I need to take a photo for a Temporary Import Permit to Mexico. Thank you, Patrick

      Started by: Patrick in: General Discussion


      2 Replies
      March 14, 2024 at 2:39 pm Got it. Thank you!!  

      Last Post by: Patrick posted: 1 week ago

    • Air in fuel lines

      This topic has 1 reply, has 2 voices, and was last updated byClark Leighs 1 week 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 in: Cummins Marine Engines


      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: 1 week ago

Viewing 20 topics - 1 through 20 (of 5,072 total)