Cummins Marine Diesel Repower Specialists Forums Cummins Marine Engines

This forum contains 604 topics and 3,723 replies, and was last updated by  Corey Schmidt 5 hours ago.

Viewing 20 topics - 1 through 20 (of 604 total)
    • Cummins Marine Forum Topics
    • 6bta Boost Pressure

      This topic has 1 reply, has 2 voices, and was last updated by Corey Schmidt 5 hours ago

      June 22, 2018 at 9:12 am What regulates the boost pressure on a Cummings 6bta? I don’t see a wastgate actuator anywhere on my turbo but I’m assuming there has to be something to prevent over boost.

      Started by:  Phillip Shetzler


      1 Replies
      Reply #1 June 22, 2018 at 2:33 pm If you have a Bosch P7100 Injection Pump, the aneroid valve is typically what interacts between the amount of fuel delivered against the amount of turbo boost pressure sensed… sometimes these valves need to be adjusted… the aneroid valve is directly connected with a boost line to the injection pump. https://www.sbmar.com/articles/aneroid-adjustment-on-the-bosch-p7100-injection-pump/ Corey Schmidt VP, Operations Seaboard Marine, Inc. …

      Last Post by:  Corey Schmidt posted: 5 hours ago

    • 6cta aftercoolers

      This topic has 6 replies, has 4 voices, and was last updated by Rob Schepis 13 hours ago

      June 20, 2018 at 12:30 pm I have a question about the attached pictures. First I serviced the aftercools per Seaboard recommended procedure. I was in the process of servicing them again and noticed the pitting between the o-ring and end cap in the attached picture. That is my starboard engine. Every thing else looks great, housing and core. What could cause this? Is it safe to put back in boat since it is outside of the 0-ring? I change zincs regularly. The second attach…

      Started by:  Dave Eberle


      6 Replies
      Reply #6 June 22, 2018 at 6:34 am JB Weld would be good, just a tad harder to work with. For the peened over tubes—an aluminum rod from the opposite end with a taper point—gently Early tubes were soldered/furnace brazed—later versions were expanded……. Way better if done right Rob "Luck is the residue of good design."

      Last Post by:  Rob Schepis posted: 13 hours ago

    • Oil change interval, QSM 11 670

      This topic has 2 replies, has 2 voices, and was last updated by Larry Backman 13 hours ago

      June 21, 2018 at 7:05 pm I’ve been slowly inching up from 150 hour intervals to 200 hr intervals on my oil changes. The operations manual says 250 hrs. My use profile is typically burning 220 gallons on 36 hr trips, ie averaging 6-8 GPH. That profile consists of 2 5 hr runs at 19 GPH, 18 hrs troll at 2.5 GPH and 8 hrs idle at 1 GPH. I typically put 7-800 hrs a year on the engine and am trying to get to 3 oil changes per year and a final one during winterization ver…

      Started by:  Larry Backman


      2 Replies
      Reply #2 June 22, 2018 at 5:53 am 800/250 is a 3 changes, 800/150 is 4-5 Changes…

      Last Post by:  Larry Backman posted: 13 hours ago

    • Netural Safety Switch

      This topic has 2 replies, has 2 voices, and was last updated by Justin Murphy 1 day ago

      June 21, 2018 at 7:24 am I am doing some preventative maint. and replacing the mag. switch on my 370hp 6bta after I was losing voltage due to some corrosion (cleaned off terminals and fixed the problem but bought the switch you sell here for peace of mind). My boat does not have the neutral safety circuit hooked up and I am interested in remedying. I have looked at the wiring diagrams here and can’t seem to figure out how to wire it. I have two leads from my ZF…

      Started by:  Justin Murphy


      2 Replies
      Reply #2 June 21, 2018 at 8:38 am Thank you, yep I will confirm that the switch is operating as intended with the multi meter. Cactus

      Last Post by:  Justin Murphy posted: 1 day ago

    • 6CTA 8.3 M1 oil in coolant

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

      June 20, 2018 at 9:14 am Hi Tony and everyone else, I was in my engine room all day today, entire saloon floor taken up for plenty of headspace and light. Was swapping out some old gear oil cooler hoses as well as some coolant vent lines on port engine, after going to the hydraulics shop yesterday. Late in the afternoon, almost everything done I changed my coolant filters. Port engine, no problem. Stb engine… after unscrewing the filter a few turns, the first liqu…

      Started by:  alex1


      3 Replies
      Reply #3 June 20, 2018 at 7:16 pm I want to start out like this………..Engine hours wise, your engine is “as new”..This is a 20000-50,000 hour engine between rebuilds when run and maintained properly. As to internal engine wear based on engine use , it is not even well matured yet…………. AS to all the rest, your issues, although I do know exactly where they are ( or even if you have any) are from a total lack of proper maintenanc…

      Last Post by:  Tony Athens posted: 2 days ago

    • battery voltage high

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

      June 20, 2018 at 3:37 pm Qsb 5.9 – battery voltage would rise up to 17 volts at high rpm then drop back to 14 at idle rpm , could it be voltage regulator and it showing on both engine with separate gauges so thinking its not alternator, Looking for help for a place to start looking for problem. Thanks

      Started by:  Frank Thweatt Jr


      2 Replies
      Reply #2 June 20, 2018 at 4:40 pm The symptom you describe would typically be related to the internal voltage regulator failing, inside the alternator. Simple to exchange alternators of take it off and have it repaired. Or do both, then you have a spare. But do follow Phil’s lead regardless.. Very important. 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

    • 6CTA8.3-M4-265 compared to a 480C-E

      This topic has 6 replies, has 3 voices, and was last updated by Rob Schepis 2 days ago

      June 19, 2018 at 1:51 pm So it seems a lot of folks are confused about these designations, the M4-265 compared to the 480C-E. I am looking at two engines with serial numbers of 46333332 and 46332307. The Cummins Quickserve Online lists them as a 6CTA8.3-M4-265, cpl2960. According to Boatdiesel, their list of data sheet from Cummins, the 480CE is listed as a 460bhp engine with a cpl of 2960. It does not list an M4-265. This seems to be confusing several folks that I am…

      Started by:  Dennis Robb


      6 Replies
      Reply #6 June 20, 2018 at 10:18 am SWAC – salt water aftercooled CPL – Critical Parts List Not sure what the “family” relates to and what significance it would be when it comes to things that matter. Yes, this is the same engine that needs to be propped down to the 450 curve as explained here: https://www.sbmar.com/articles/propping-cummins-6cta-8-3-480ce-vs-430450-diamond-engine/ Rob "Luck is the residue of good design."

      Last Post by:  Rob Schepis posted: 2 days ago

    • 6 bta air heater question

      This topic has 2 replies, has 2 voices, and was last updated by Mike P 3 days ago

      June 19, 2018 at 3:40 pm Have just recently repowered with 6bta’s. My port engine starts and runs well, with very little smoke after initial startup. The starboard engine is hard starting, needing me to cycle the air grid heater on and off for two to three cycles before it will start. I know it is working as I see the voltage drop and can hear the clicking sound of what I would guess to be the relay. Once started it smokes excessively with white smoke. After…

      Started by:  Mike P


      2 Replies
      Reply #2 June 19, 2018 at 5:38 pm I’d greatly appreciate the guidance and will post on how it goes. Please keep the guidance relatively simple as I am much more a fisherman and much less a mechanic.

      Last Post by:  Mike P posted: 3 days ago

    • Excessive load percentage and lack of power

      This topic has 4 replies, has 4 voices, and was last updated by michael gallagher 3 days ago

      June 14, 2018 at 8:16 pm I have a pair of 2005 QSB 5.9’s in my 36 Tiara Open and having issues with starboard side. The engine is making excessive vibration at all rpm’s, will not turn up to max rpm under load, show’s 10% higher load at idle rpm and is 20-30% higher load when at matching throttle rpm’s and percentage of throttle. Without the assistance of the port engine the starboard will not reach 2000 RPM and when both engines are at WOT, it…

      Started by:  michael gallagher


      4 Replies
      Reply #4 June 19, 2018 at 5:20 pm As luck would have it the problem was found by a 4th set of eyes prior to any lap top diagnosis. One of the connectors on the top of the engine which is connected to the 5 and 6 cylinders separated enough to cut off the two engine cylinders. With a tiny squeeze my issue went away thanks to a butt connector. Thanks for the helpful responses that you all provided.

      Last Post by:  michael gallagher posted: 3 days ago

    • Smoking 6bta 1 2

      This topic has 22 replies, has 4 voices, and was last updated by Stephen Oliver 3 days ago

      April 28, 2018 at 5:35 am Keel cooled JWAC 6BTA, CPL CPL953. Tach is 200 high. Unknown hours WOT is 2750 RPM photo tach. 32’Novi, 17,000lbs,2.57:1 gear with a 23×26 high cup wheel. After 1300 RPM she starts smoking, black to brown. The engine is not the easiest to start in the cold, I crank it without fuel for 10-20 seconds then start and she will start 20-30F. Spring/Summer temps it has no problem starting. Blowby appears fine, no test done to measure……

      Started by:  David Wesner


      22 Replies
      Reply #22 June 19, 2018 at 2:38 pm If you look at holsets ‘counterfeit’ guide – then having a hex nut on the compressor side is a sign of a counterfeit turbo… normally its a multipoint nut. Its probably worth giving Holset a shout and giving them the pictures / serial for them to check.. Steve Steve - Perth - Australia

      Last Post by:  Stephen Oliver posted: 3 days ago

    • Turbo – Rebuildable?

      This topic has 11 replies, has 3 voices, and was last updated by Stephen Oliver 5 days ago

      May 23, 2018 at 3:36 am HI Guys Putting my port engine issues aside – I decided rather stupidly to replace the wet elbows on both engines as they both have a weep – I started with the port engine as prior to the rev’s / power issue I was going to do the aftercooler and HX maintenance – so thought I better go through them anyway as blocked aftercooler etc is probably one of the things i need to investigate. Anyway after noticing the port elbow wa…

      Started by:  Stephen Oliver


      11 Replies
      Reply #11 June 17, 2018 at 4:13 am Hi Tony Totally agree. It’s unfortunate that so many boats suffer the same fate.. you would think that the boat builders or cummins would address it, but when they can supply expensive parts regularly and new engines after 1000 hours or so.. why would they! Anyway new risers (inspired by SBM) and new mufflers are on the to-do list. Steve Steve - Perth - Australia

      Last Post by:  Stephen Oliver posted: 5 days ago

    • Target Revs for 330 Diamond 6BTA 1 2

      This topic has 31 replies, has 4 voices, and was last updated by Stephen Oliver 1 week ago

      May 4, 2018 at 12:33 am Hi Guys What revs am I looking at achieving WOT for the 6BTA 330 Diamonds ideally (approx 1700 hours) Boat is back in the water finally with new props (20×21 4 blade mikado) Port engine is topping out just over 3000rpm and starboard side wont run that high as the throttle is at max before it gets there (its out position wise compared to port engine much further forward at same rpms – so think its just a cable issue – something i…

      Started by:  Stephen Oliver


      31 Replies
      Reply #31 June 14, 2018 at 10:18 pm HI Guys Just as a follow up – i believe (although not confirmed yet until new turbo is fitted) that the issue was a well and truly worn out turbo (salt water worn) see https://www.sbmar.com/community/topic/turbo-rebuildable/#post-33525 I suspect there was just very low boost available and therefore down on power – just the STB engine was pulling the port engine along and masking the issue – I also suspect the black smoke couldn…

      Last Post by:  Stephen Oliver posted: 1 week ago

    • White smoke from dipstick and oil cap

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

      June 8, 2018 at 8:19 am I have an idea but appreciate all input & advice. My Cummins 370hp 6bta 1k hrs #45916445 Stbd motor has a light puffing white smoke from dipstick and oil fill cap. It’s light on startup and increases as the engine heats up with idle. I noticed antifreeze loss from from reservoir at the end of last season (approx 1/3 gallon per50hrs). I have not done an oil analysis due to a fresh oil change (proper level). I do not have any white smoke or …

      Started by:  Baldassare Gerardi


      1 Replies
      Reply #1 June 14, 2018 at 7:30 pm Let’s start with this: I want to see really good pics of your installation from all angles & perspectives-I especially want good pics of you exhaust system, and aftercooler & turbo……………..How do you know what your blow-by numbers are? Last time your aftercooler(s) was put on the bench and serviced per my protocol? 1000 hrs and having issue requires “new eyes” & thoughts about what…

      Last Post by:  Tony Athens posted: 1 week ago

    • 6BTA throttle lever arrangement

      This topic has 3 replies, has 3 voices, and was last updated by Tony Athens 1 week ago

      June 14, 2018 at 3:43 am Hi I have a rebuilt 6BTA 300hp with Nippon Denso fuel Injection pump which I want to build into a 20 metre survey vessel for slow speed running. The main engines are Detroit 8V92T at 500 hp each, the 6BTA will replace a 4BTA which achieves 6 knots in calm water I need 8 knots with newer survey equipment. Does anyone have any photos or ideas how to arrange the throttle system so that the control cable leads from aft. The aftercooler has just been…

      Started by:  Bob Fitch


      3 Replies
      Reply #3 June 14, 2018 at 6:56 pm 1)———-what ever you have on your CAV pump IN NOT applicable the the EP( pump.. 2) Way easier to just install an longer cable , go around the back of the engine and do it. 3) Pic of the other way attached too. 4) In both cases you will be fabricating custom brackets 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 lo…

      Last Post by:  Tony Athens posted: 1 week ago

    • New owner of a 38 Bertram Convertible with 6CTA 480ce's – immediate priorities? 1 2 3

      This topic has 47 replies, has 6 voices, and was last updated by Nicholas Cummings 1 week ago

      October 13, 2017 at 10:07 am Just closed on a B38 powered by 2002 6CTA’s with about 1500 hours. This is my first diesel boat so I’ve spent the last month or two pouring over this site and some others to get educated. In 2016 the engines had heads rebuilt, turbos rebuilt, aftercoolers and heat exchangers serviced, and new injectors installed. One engine also had a piston, liner, rings, and bearings replaced and the other got a new belt tensioner and serpentine…

      Started by:  Nicholas Cummings


      47 Replies
      Reply #47 June 13, 2018 at 7:37 pm Well, the tech who did the work for me thought perhaps the cores hadn’t been removed, but cleaned some how in place. We were puzzled though because the damaged tube ends made it seem like someone had hammered the cores out. But Rob’s explanation of the zincs bouncing around damaging the tube ends might explain how that could have happened. So I guess my “forensic” theory would be that perhaps the cores hadn’t been removed in……

      Last Post by:  Nicholas Cummings posted: 1 week ago

    • 190 degrees too hot for QSC 8,3 540?

      This topic has 4 replies, has 2 voices, and was last updated by Ron Carter 1 week ago

      June 10, 2018 at 2:10 pm This is a single engine 2006 42′ Nordic Tug with the above single engine. 1450 hours since new. Aftercooler and all exchangers taken off boat and professionally cleaned in November 2016, Salt water environment in SW Florida. Bottom is cleaned monthly. Last clean 10 days ago. Fuel on board is 525 gallons or about 3600 pounds. Fresh water on aboard is 175 gallons or about 1200 pounds. I usually cruise at 1650 rpms at a temperature of 170 d…

      Started by:  Ron Carter


      4 Replies
      Reply #4 June 13, 2018 at 2:56 pm Took most of the overload off and got a good bottom clean from diver and she ran like a scalded dog at 182 degrees WOT on official pre-sale sea trial. All is well.

      Last Post by:  Ron Carter posted: 1 week ago

    • Idiot's guide to the 6BTA 5.9 Maintenance

      This topic has 8 replies, has 7 voices, and was last updated by Nicholas Cummings 1 week ago

      May 4, 2017 at 9:22 am Hi everyone.  I’m new to this board, and new to owning a yacht.  I have a Carver 404 with twin 6BTA 5.9 370 HP engines.  It had a mechanical survey, but I am learning that the person who did this was not very good.  I recently had to have my port gear replaced, and during that, my mechanic let me know that the aftercooler needed rebuilding.  My point with this is I didn’t even know that aftercoolers needed regular maintenance un…

      Started by:  Rick Pederson


      8 Replies
      Reply #8 June 13, 2018 at 12:32 pm Go to cummins website and register your engines with your serial numbers. Once you have done that you should have access through their website to the owners manual and O&M manual for your engines. The O&M manual has the basic recommended service items & interval. I built myself an excel spreadsheet checklist using that basic data because it can be a little overwhelming. Keep reading the articles here and search for forum posts from …

      Last Post by:  Nicholas Cummings posted: 1 week ago

    • cummins/vdo tach

      This topic has 5 replies, has 2 voices, and was last updated by Tony Athens 1 week ago

      June 6, 2018 at 1:56 pm Hi all, I have a Cummins 6BTA with an alternator driven VDO 4″ tach. I am replacing the tach because it will intermittently stop working. The original is no longer available. I installed a FARIA unit (actually 2) and got no reading. Tach needle bumps when I switch on the key, but no rpm reading. I measured about 3v ac at the signal wire. If i reinstall the VDO it reads fine. The Faria unit is correct for alt-driven application according to…

      Started by:  Jerry


      5 Replies
      Reply #5 June 12, 2018 at 7:10 pm Need to see full back & front pics showing the fan and pulley–Yes, you have a DELCO 3-wire unit–Probably a 15SI.. 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

    • 370B max RPMs

      This topic has 11 replies, has 6 voices, and was last updated by Bill Desmarais 1 week ago

      May 29, 2018 at 8:41 pm Just splashed the boat for the season and on the first run I checked WOT rpms and came up short on the starboard motor. It only reached 2985 on digital tach. I just had the props tuned to the same specs from previous years. Previous results were 3085 on starboard and 3100 on port. The Port hit 3070+. Also the bottom was stripped and completely redone in the off-season so I was hoping for even better numbers than I got. I did notice the st…

      Started by:  Richard Sosdorf


      11 Replies
      Reply #11 June 12, 2018 at 5:50 pm Richard Sosdorf wrote: Bill thanks for the response. I’m still trying to figure out what going on with the loss of RPM’s. Tony ? Whadda ya think ?? 25 Terry Jason down east, 370 6BTA 28 Henriques Sport Fish, twin Volvo 200 41 PA s

      Last Post by:  Bill Desmarais posted: 1 week ago

    • water take off from SMX 1730 pump

      This topic has 12 replies, has 4 voices, and was last updated by Michael Starr 1 week ago

      June 5, 2018 at 12:27 pm Engine is 6BT 210. I recently replaced the trans cooler with one that has the two zincs. The cooler that came with the engine only had one small outlet that was used to supply the dripless shaft seal with cooling water. The new unit has openings for the two zincs. I wanted to keep the two zincs in the tube so I was looking for another location to get water to cool the shaft bearing. I found two plugs on either side of the SMX impeller cover. I …

      Started by:  Michael Starr


      12 Replies
      Reply #12 June 12, 2018 at 10:21 am I appreciate all the advice. I contacted Tony and he sent this article FYI. Best Locations to get Water Flow for Shaft Packings Mike

      Last Post by:  Michael Starr posted: 1 week ago

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