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High coolant temp alarm
This topic has 3 replies, has 2 voices, and was last updated by
2 years ago October 17, 2021 at 4:41 pm cummins 250 CPL953 I get a high coolant alarm from my high temp switch on the exhaust manifold port. Engine alarm doesn’t sound from the original instrument panel. I will be installing the 1″ banjo at the turbo and line to the rear head coolant port. My question is…by increasing the flow out of the head to the turbo, what is done from the exhaust manifold to the circulation pump? I only see one outlet from the exhaust manifold …
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in: Cummins Marine Engines
3 RepliesOctober 31, 2021 at 1:29 pm Discripive or not, your picture adds to my lack of understanding what you have.. I know the cooling system of a B very well but look as what you have posted:,, No clue as to what you have going on–Certainly nothing that I recogognize HX or keel cooled? Properly sized? Expansion tank location & size? De-aireartion or spitter lines to the expansion tank??? The one I see at the elbow at the thermostat outlet looks like it goes down or s…Last Post by:
posted: 2 years ago
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Sea Trial Numbers
This topic has 2 replies, has 2 voices, and was last updated by
2 years ago
October 17, 2021 at 4:10 pm 250 Cummins CPL 953 FWJAC Any comments on numbers are appreciated.
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2 RepliesOctober 29, 2021 at 9:37 am Thanks. Why do you point out 7-8kts? Curious, because at the point I’m only burning about 2+ gph. Is it the EGT, percent RPM, or something else. I do typically cruise at 8-9 kts. I do know the hull isn’t capable of higher speeds.Last Post by:
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damper plate rubbing on gear
This topic has 4 replies, has 2 voices, and was last updated by
2 years ago
October 11, 2021 at 11:52 am IĀ“m having interference problems with a cummins 6bta and velvet drive. The damper plate (velvet drive) is rubbing against the gear (velvet drive 72C). Almost like there is supposed to be a gasket or shim between the adapter plate and the gear. Any help would be appreciated. D
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4 RepliesOctober 12, 2021 at 12:36 pm awesome, good luck to ya!Last Post by:
posted: 2 years ago
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reverse gear ideas
This topic has 1 reply, has 2 voices, and was last updated by
3 years ago April 26, 2021 at 8:25 am Presently running a 6BTA 250hp cummins in a workboat. It has a velvet drive 2.5:1 gear. I’m looking to upgrade the gear to something more robust. I’ve seen a few MG506/507s around. I’ve been advised that these might be a good candidate for replacement. Most likely the boat will need a new shaft to make up the different case measurements. I am also thinking of changing the gear ratio to 2:1 to bring a new prop to 23″ squar…
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1 ReplyMay 1, 2021 at 5:27 pm The MG506 & MG507 are both “good ol” gears, but both have been out of production for over 20 yrs now.. Lots on them still around and both are easy to rebuild as gears go as long as the gear is in “still working condition” and is not a total rust bucket. With that said, the MG507 would not be an easy gear to adapt to any B series Cummins ( clearance issues with the turbo and possibly other things). From experience, th…Last Post by:
posted: 3 years ago
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hydraulic pump install
This topic has 4 replies, has 3 voices, and was last updated by
3 years ago September 22, 2020 at 6:20 am Any advice on installing a 24gpm gresen hydraulic pump on the front end of my 250 6bta cummins. Presently have a 12gpm pump run off the dual pulley adapter on the front crankshaft. As anyone with a pulley driven accessory it is less than desirable. Engine is hard mounted. Does the small drive shaft need to be exactly square to the crankshaft or is a small angle needed for cv joint articulation/lubrication? Driveshaft guard needed? Special tool …
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4 RepliesSeptember 22, 2020 at 11:20 am I really don’t know why the offset to be honest. I used a digital protractor. pretty easy to set up. you can just change the rings in your pump and get 24 gpm. The drive shaft is the best way to go but a lot of work to convert over to it.Last Post by:
posted: 3 years ago
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Ground Wire
This topic has 5 replies, has 4 voices, and was last updated by
3 years ago June 10, 2020 at 5:26 am What is the “best” spot to attach the negative cable on the engine? Mine is on the rear head bolt and I suspect it isn’t the best spot. Thinking of starter bolt. Also, bolt size if know so I can order the correct lug for the cable. Thanks in advance. D
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5 RepliesSeptember 22, 2020 at 10:59 am David Wesner wrote: curious, why lithium grease? thx D Just an old school OEM protectant for cable connections and the like, if you have a non-conductive flavor of choice go ahead and use it.Last Post by:
posted: 3 years ago
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4LH sudden power loss
This topic has 1 reply, has 1 voices, and was last updated by
August 2, 2020 at 3:09 pm Last week ran the boat from the yard to the mooring. Ran it at cruise, 3000RPM for about an hour then the engine suddenly lost power and died. Immediately thought of fuel filters but was surprised at the abruptness. Bled lines, cracked injectors and got it running. Unable to power up again, idled to mooring which was pretty close. Next day, changed the RACOR and secondary. Racor was pretty clean, secondary was pretty dirty. No change, no power. …
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1 ReplyAugust 2, 2020 at 6:06 pm suspect check valve in lift pump on outlet? Thoughts?Last Post by:
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High coolant temp and low oil pressure alarm
This topic has 2 replies, has 2 voices, and was last updated by
March 28, 2020 at 6:58 am I’m getting a high coolant temp and a low oil pressure alarm when the engine warms up. I’ve confirmed this is not actually happening with a mechanical gauge and an IR temp gun. Also, I have a secondary set of alarms purchased here at Seaboard. I do believe this is ground issue. Any pointers on where to look? Using the voltage drop method with the DVMM is the best way to trace it out? I believe the panel ground goes into the harness …
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2 RepliesJuly 19, 2020 at 6:40 am So… looked through some schematics and saw how it was wired. Instead of chasing the wire loom, I jumped the ground from the negative bus to the ground connection on the IC board. Seems to have fixed the false alarms. Iāll take some voltage potential readings to confirm. The wire loom has some ground connections on the starter that look fine. Suspect connectors or…unused ground for the fuel stop solenoid. DLast Post by:
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waste gate purpose?
This topic has 1 reply, has 2 voices, and was last updated by
4 years ago March 29, 2020 at 4:54 am So, some engines have them, some don’t. I understand the principle, but am unclear “why”. My best….thoughts are that the air stream velocity could float the valves??? D
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1 ReplyMarch 29, 2020 at 8:02 am To allow more boost at lower engine output, gives a much fastest torque rise (like in the 1200-1800 RPM range ) when accelerating trying to get up on plane ( that also lowers dark smoke big time) but limit the boost at high power output/WOT where the waste gate can open to limit boost and limit compressor turbine RPM.. The linkage movement is very small and not easily seen.Last Post by:
posted: 4 years ago
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exhaust design
This topic has 6 replies, has 2 voices, and was last updated by
March 1, 2020 at 7:55 am So, I’m having issues with water getting back into my turbo. Thought I had safe design, but obviously it isn’t working. I think part of the problem is the roll back during stopping that I understand to be common with 4 cylinder diesels. Using a stock yanmar mixer, going to 3.5 hose approximately 4′ long with a good pitch to a water lift muffler. The water lift muffler sits forward the engine and discharges up at into the cabin …
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6 RepliesMarch 1, 2020 at 10:43 pm Great talking with you and thanks for your time! Iām very comfortable with mechanical, glass and some welding/fab work. Changing the effects of gravity is something I havenāt been too successful at but really am curious to your thoughts on the redesign. DLast Post by:
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Yanmar coolant plugs for heater
This topic has 2 replies, has 2 voices, and was last updated by
February 10, 2020 at 3:42 am I’m looking for information on the correct type of fittings for the heater ports on a Yanmar 6LYA-STE. The service manual calls them 3/8″ pipe threads. They are either NPT or BSP. Measured what was on the engine and it appears they are NPT as they are slightly larger than the BSP. Did someone wind them into the BSP female threads before I got the engine. What is it supposed to be? thanks D
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2 RepliesMarch 1, 2020 at 8:02 am Thanks for the info. Spoke with mack boring and they confirmed it was BSP 3/8″. Removed old plug and saw some thread smashing. I was able to fit the BSP fitting without concern. Posting for anyone else looking for the information. DLast Post by:
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Yanmar 6LY coolant
This topic has 7 replies, has 4 voices, and was last updated by
4 years ago January 28, 2020 at 7:53 pm I know it may be beating a dead horse, but I’m having trouble understanding what coolant to use in my new to me 6LYA-STE. I’ve done research, not a lazy no search question. The literature from Yanmar is a bit outdated, they recommend Coolant from Havoline or Texaco. The Havoline ELC is now orange. I have read that the red coolant is what is to be used. The Havoline ELC (orange) is silicates and nitrate free OAT. Delo ELC is red, sil…
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7 RepliesJanuary 30, 2020 at 5:47 pm I have 4LHA-STEs which have the same coolant issues as your 6LYAs. The key is, and I think this is in the Yanmar spec someplace, is that the coolant have no silicates or phosphates. I have used Preston Dex-Cool Extended Life coolant for 20 years with no problems. Any brand of Dex-Cool Extended Life should be OK as long as you can find some place on the label that says “silicate and phosphate free”. These are all orange in color. If …Last Post by:
posted: 4 years ago
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Hour meter install
This topic has 4 replies, has 2 voices, and was last updated by
4 years ago December 30, 2019 at 12:08 pm What is the best way to install a new hour meter to the panel. The integrated one has failed. I have a Hobbs unit to install. 6bta circa 1997 12vdc. Thx D
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4 RepliesDecember 30, 2019 at 2:49 pm Oh OK…. easy, just wire it to your IGN circuit so it only run when the key switch is “ON”… one wire to DC NEG, the other to the PURPLE IGN wire off the key.Last Post by:
posted: 4 years ago
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Fuel Return Line
This topic has 2 replies, has 3 voices, and was last updated by
4 years ago December 13, 2019 at 10:54 am Why does the fuel return line typically go back to the tank. I’m looking at a toyota engine (2B, 3.2 liter) and they have engineered the fuel return line from the injectors to enter the suction side of the feed pump. Thanks David
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2 RepliesDecember 15, 2019 at 4:21 pm Many modern smaller engines do that, and some do not even have a return that you see externally..All internal. No clue how it works, other that it seems that engines like this are way harder to bleed if you have to start fresh for some reason.. A squeeze bulb is just about required to do it.Last Post by:
posted: 4 years ago
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Smoking 6bta
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This topic has 31 replies, has 5 voices, and was last updated by
5 years 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……
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March 10, 2019 at 12:28 am Glad to see you resolved the issue David. Going the same route with two 6BTA JWAC engines in a new to me boat. Max I can get is app. 1600 rpm with a huge amount of black smoke. Traveled from Batam, Indonesia, to Port Klang Malaysia (app. 300 NM) at a painful 1250 RPM. Using Seamax instruments and exhaust temp was constant at app. 850 deg, not yet wired up boost gauge. Am thinking that vessel, Baha Cruiser 310 SF, had petrol Volvo’s origina…
31 Replies
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posted: 5 years ago
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Aftercooler coolant tube leak
This topic has 3 replies, has 2 voices, and was last updated by
5 years ago October 12, 2018 at 6:35 am Anybody have any experience dealing with a leaking coolant tube on a 250 cummins FWAC CPL953? The small weep is at the connection to the head in what appears to be a freeze plug. I am going to call today for availability of the replacement part. Item 22 in the attached diagram. D
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3 RepliesOctober 15, 2018 at 7:48 am Same to me??Last Post by:
posted: 5 years ago
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CAV pump timing
This topic has 6 replies, has 3 voices, and was last updated by
August 8, 2018 at 4:17 am Need some help in determining if my CAV injection pump is set correctly. It does not match the descriptions in the manuals available on the Quickserve site. Engine symptoms are black smoke, light at idle to heavy after or near hull speed at 1300-1400 RPM. CPL 953 Inspection window on the pump shows the scribe H at the circ clip at TDC. Am I interpreting this correctly and what needs to be done to correct the issue. Thanks D
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6 RepliesOctober 5, 2018 at 1:53 pm Turned out being an injector that wasn’t seated correctly. Number 5 injector was not sitting all the way into the injector seat. Engine runs smooth with zero smoke now.Last Post by:
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Opinions on gear/engine match
This topic has 9 replies, has 2 voices, and was last updated by
November 5, 2017 at 5:14 pm Just bought a workboat with an older JWAC 6BTA, 250. It has a velvet drive 72C gear, can I expect issues down the road and what would a Heavy Duty replacement gear option be. Presently have a drive saver in line, so there is an 1.5″ or so extra length available if needed. David
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9 RepliesMarch 20, 2018 at 7:18 am 10-4Last Post by:
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Cummins Oil Spec
This topic has 2 replies, has 3 voices, and was last updated by
6 years ago February 12, 2018 at 7:40 pm So, New to me 6BTA keel cooled with Cav pump. No smoke from crankcase vent when cold. When the engine warms to operating temp I start to see more mist from the breather tube. From what I have read on the forums, this may be due to too much oil in the pan. I’m going to change the oil and filter and start fresh. I’ve also read on the correct level, but am getting some different amounts depending on the thread or article. Is it 8-9 qua…
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2 RepliesMarch 8, 2018 at 8:28 am David Wesner wrote: So, New to me 6BTA keel cooled with Cav pump. No smoke from crankcase vent when cold. When the engine warms to operating temp I start to see more mist from the breather tube. From what I have read on the forums, this may be due to too much oil in the pan. Iām going to change the oil and filter and start fresh. Iāve also read on the correct level, but am getting some different amounts depending on the thread or article. Is it…Last Post by:
posted: 6 years ago
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water pump inlet hose 6BTA
This topic has 2 replies, has 2 voices, and was last updated by
January 31, 2018 at 6:27 pm How do you get a 2 1/4″ wire bound hose to fit the 58mm OD inlet for the coolant pump? I tried heat and wrestling that hose and I am contemplating going with a poly bound hose because I cannot get the wire reinforced hose to get on the inlet barb. Application is a 250hp keel cooled vessel. D
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2 RepliesFebruary 2, 2018 at 9:02 am The engine is CPL 953. The issue is the 58mm inlet to the engine has a barb that is just too big for the wire bound 2 1/4″ to slide pass. Ended up getting a poly bound hose that can be installed much easier. I really do wish I could have installed the wire bound hose and I hope that the poly bound non reinforced hose will be sufficient and not collapse or cause issues. The hose is 43 inches from the pump inlet leading aft to a gear cooler …Last Post by:
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High coolant temp alarm
