6BTA 270 LOW POWER, TRIED EVERYTHING PLEASE HELP!!

[Maxime Barthe]

Hi Everyone,

First off i’m new to the board even though i’ve been browsing between here and a few other forums for a while. My name is Max, I live in Pompano beach, FL and I have an awesome 28′ WhiteWater with a cummins 6BTA 270 paired with a fixed surface drive. I recently upgraded about a year ago from my old 25′ Aquasport with outboard power and finally purchased my dream boat. This is my first Diesel boat, though my father has a 1969 Hatteras 45′ with twin Luggers and we’ve pretty much done or had everything done to these engines over the last 10 years.

My boat lived its entire life in the Bahamas only being used about 1 month every year and lived on dry-dock the rest of the time (until i purchased it) when i purchased the boat she ran great, but i knew i would run into a few issues being that it was not used regularly. (only had about 500 hours at the time of purchase) as soon as i got the boat home i drained the fuel tanks, changed the oil, all the filters and replaced the coolant and the impeller. the boat ran great and i took her to the Bahamas with no issues. about 2 months ago the boat began taking a really long time to hit boost and get up on plane, and now the boat will not hit boost at all or get up on plane. (ABSOLUTELY NO DARK SMOKE). She starts right up and runs perfect at low RPM and does not bog at all when i try to accelerate, it just hits a wall and stops accelerating. I went through everything with my limited mechanical abilities and checked the fuel solenoid, filters, fuel lines, racor, ran a direct fuel line from jerry can – eliminating fuel flow issues etc.

So here is the crappy part about all of this. I hired a mechanic after i could not find out the problem and he explained to me that i should change the injectors, i was planning on doing them soon anyways so i was fine with that. of course it did not fix the problem. next he recommended rebuilding the injection pump, i did so reluctantly and it did not fix the problem, although according to the company that did the job it was in poor condition. last and not least he was absolutely positive that the turbo was the issue (ill admit it was in pretty rough shape) but i was not getting dark smoke so i did not think so. either way i had the turbo rebuilt. of course this did not fix the problem. so now i’m $5,000 in the hole with replaced parts and my boat is still doing the exact same thing.

Needless to say my mechanic feels horrible and is not charging me any labor for the replacement of all these parts but that still does not help the fact that i dumped 5 grand into the boat and it did not fix my problem. I’m at the point where i have no idea what to do. he’s coming back with a bore scope to look at the lifters and valves etc but i have a feeling he might just be spinning his wheels.

if ANYONE has some advice to help me get my dream boat back up and running the way she would i would be thrilled.

i have a feeling it has to be something stupid but truthfully i have no idea

The only thing that has happened to the boat before this was that my exhaust coupler had a minor leak and was dripping right on the PTO shaft housing. this in turn was shooting small amounts of water onto the wiring harness and maybe elsewhere. this caused the harness to corrode and need to be replaced. none of this had any adverse effects on the performance of the boat.

PLEASE HELP ME I NEED TO GO FISHING BEFORE I LOOSE MY MIND!!

Topic

[Tony Athens]

It does sounds like you are not getting fuel and it could be related to the post above about the clogged boost line, or this article…No boost=No Fuel= no power and no dark smoke

Aneroid Adjustment on the Bosch P7100 Injection Pump

Put together a “kit” with a hose, a pressurized air can (like used to blow out your computer) and a 0-30 PSI gauge.. Hook it up to the boost line that goes to the aneroid. Plug the side that goes to the engine. Bring the pressure up to 15 PSI and go for a ride.

Next———— Have you measured fuel pressure on the on-engine filter??–It should stay above 15 PSI at all times.

Start there.

Tony

[fpetrill]

Hi
I had exactly the same problem with a 6bt 370 mounted in a 24 ft. AMF attached with a arneson surface drive with a 1.567 ZF gear and a 6 blade 30 X 29 prop,

At wot hit 2600 rpm no smoke but no power, was difficult to get it to plane with more than 4 people on board, I had to tilt up the prop to get 2800 rpm.

I was focused on the fuel consumption, it was only 6 gph, after some research I found the problem, and now with the prop tilt down planes in seconds and I have to pull back the throttle because the rpm climb to 3500 if I don’t keep an eye in the tach. even with 12 people on board, and easy goes at 35 Kn. at 2900 RPM.

Now I have to change the prop to use all that power.

What was happening is that the hole in the pressure line that goes from the intake manifold to the injector pump (A plastic tube) was clogged with rust in the pump side, and there was no boost pressure signal in the diagram that opens more fuel to the engine to develop full power.

Hope it helps

[Tony Athens]

” solved the low power issue”

Tell me what your maximum RPM is loaded the the way you use the vessel?

You have finally verified your tach readings, correct?

Maximum NO LOAD RPM?

Just need a 100% accurate numbers?

Tony

[Maxime Barthe]

Bill,

Thanks for your response. I’m confidant that the guys here at SeaBoard will help get me going reliably and safely. I have zero doubts that anyone on here would lead me in the wrong direction and i’m thankful for that. Every day i work on my engine i feel i get to know it a lot better. i’ll be addressing tachometer//temperature gauge issues this weekend. along with hopefully replacing a few leaky gaskets.

[Bill Desmarais]

Maxine,

I was in your position exactly 10 yrs ago when I bought a 1996 Blackfin with highly used and I think abused pair of 6BTA 370s.

Same as you I, I had the new to me “boat fever” and spent $16,000 “freshening them up” as you have with the $5,000 into the 270.
Same as you I was “new” to marine diesels but knew enough to know I wanted a boat with “Cummins”.

Looking back I put a lot of the $16,000 into the engines that was not really needed. And his the best part.

Uninformed me (ya I was pretty dumb to marine diesels…never owned one til I bought the Blackfin.
The $16,000 did not include redundant alarms. After I spruced up the engines and boat I figured I was “all set”..marine diesels last forever…never stop running…right ?

Stupid me….with all the time and effort and money when I splashed the boat neither engine had “High Temp” alarms. Looking back I can’t believe how dumb I was.

Long story short…I rare mechanical fluke occurred on the port engine cruising @ 2400 rpms. The idler assembly snapped off and with it the serpentine belt that spins everything up front including the fresh water water pump. NO alarm…engine overheated real good and burnt 3 pistons, cracked exhaust manifold, all of it…engine was junk after. Come to find out after the fact both 370s had been rebuilt once or twice. $70,000 later with labor, my time etc., two new ReCon 370s setup the Seaboard Way tricked out and alarmed to the teeth solved the problem with new exhausts etc. all from Seaboard.

OK,,,,my point to this story. Follow Tony’s lead on everything of concern with your 270 and propulsion.

Sept. 2008, Tony and I developed a working/ friendship relationship on “me learning” everything I could from him. Ten yrs later and I own my fifth 370. I bought all three new ReCons from Tony.

Today, I know every inch of a 6BTA, how to maintain it, prop it, and MOST importantly making sure the engine/s alarmed to the teeth.

Keep us posted,

Bill D

1 user thanked author for this post.

Bob Patterson

[Maxime Barthe]

UPDATE 3/13/18

Good evening guys

The refurbished After-cooler has been installed and has solved the low power issue.

I took the boat for a sea trial and she did 29.5kts with my 1.5yr old, my wife 100 gallons of fuel and I. (which i think is pretty good because that’s about 1kt faster than shes ever gone

going to install the Envirovent this upcoming weekend and get all the tachometer readings. (borrowing phototach)

the boat has a tappet cover gasket leak i’m going to address while shes out of the water along with a few other minor issues (rust prevention etc)

i still havent gotten around to drawing up an exhaust diagram to try to get an idea on how to better my exhaust situation, but i’m planning on doing that soon.

i just wanted to inquire about one more thing that may potentially be affecting my performance a bit.
I’ve attached pictures of my prop/rudders. if you notice the rudders have plates that have been welded to the bottom and they’re slightly pitched upwards. i believe this is pushing the stern of the boat down forcing me to trim the bow down to get the boat to plain out more quickly.. Any ideas? i’ve been considering chopping them off just to find out for a while now but i don’t want to waste my time.

Thanks again for all the help so far guys, i appreciate everything greatly.

– Max

[Philip]

Max

Best way to work with you tach is to get yourself a laser photo tach (they are cheap) and compare rpms from idle to max at 200 rpm intervals. Often the errors +/- at one rpm will be different at another rpm. Once you have that dad you can make a calibration chart of displayed vs actually rpm and move forward.

Phil

[Maxime Barthe]

UPDATE

I finally found some time to work on the boat.

JWAC has been removed and was sent to a local shop that specializes in marine aftercoolers (3 star radiator).
It was filthy on the inside and might have been preventing the AFC line from adjusting the aneroid as rpms went up. when we pulled the line it had large amounts of vaccum both under load and not.

Envirovent filter is being sent out today along with heat exchanger maintenance kit. and walker Airsep will be making its way to the garbage.

I’m a bit concerned about an exhaust re-design as i barely have any room by the turbo when the main floor hatch is closed (ill attach some pictures later) i might have to consider a turbo relocation to top mount in order to achieve the “hump” the turbo is located about 18″ above the water line but im pretty sure the raw water exit is only about 6″ above the water line with no hump.

What are the odds the Exhaust manifold would be restricting air flow outwards? if so would it be worth inspecting while the heat exchanger is off?

EDIT: I also tested the tachometer and found that it was not pinning when power was jumped to the signal wire. It was barely jumping (hit about 400rpm max on the gauge) so i will probably be purchasing a new tach shortly.

Thanks

-Max

[Philip]

Don’t waste time doing compression, borescope, or any other stuff…..

Read this several times to start to understand how to modify your exhaust. Post a drawing (picture of your drawing) as installed and as you intend to modify and we can give advice from there….

Designing a Marine Exhaust System

[Maxime Barthe]

Philip,

Thank you for your response. I most certainly will go about following those instructions. I knew nothing about the “Hump” and I’m curious if i could have my current exhaust modified to to meet the proper specifications. i’ll splash the boat Friday night and try to get some good pictures. Once I pull the boat back out i’ll remove the aftercooler and have it professionally serviced. should i consider having the engine bore scoped and compression tested or will the no load RPM pretty much answer those questions?

I’m looking forward to going through this learning curve, and the CCV is going in the garbage, I couldn’t figure out how to apply credit with ordering online but i’ll call tomorrow and order the envirovent filtration system. Also i’m having trouble locating a part number for the JWAC gasket and or core seals.

Thank you

-Max

[Philip]

Tony has given you the info you need to proceed. Follow his advice step by step and you will be good.

I noticed you questioned the aftercooler service, just do it. No one is here to benefit any other way than to solve your issues. Read up on this site as to proper servicing and what lack of proper service means.

The exhaust design needs to go up out of the turbo before turning down and introducing cooling water, that’s called the hump and it’s what keeps the water and moisture out of your turbo and engine. That hump needs to be post turbo pre lift muffler. Not post lift muffler, You think your exhaust design is ok but can you explain how your turbo ate saltwater? Because I can run a hose on the outside and it won’t get to the inside.. if it did then your exhaust would be coming out as well.

I wouldn’t be using a mechanic that led me down a path that didn’t fix my problem even if it was free as he clearly doesn’t have the knowledge or experience. You say your skilled so there is nothing here that you can’t do yourself.

Follow the advice…. we will get you fixed and running reliably without future issues without spending unnecessary $$$. But if you do other stuff then you will be spending $$$$ blindly.

1. Toss the factory ccv
2. service the aftercooler
3. get your tach working and post no load rpms
4. Put the boat in water and get the pictures as requested

Your in the right place and on the right track… Let us know how it proceeds.

Phil

[Maxime Barthe]

Tony,

The magnetic pick-up has been located. Tony i hope you understand the reason i am here and asking these questions is because i’m trying my best to solve a problem that my mechanic could not. My friend Chris who is a certified cummins mechanic is coming over to help sometime this week. my Current mechanic is working for free until the problem is solved, but i want to have the best understanding i can about my engine so i don’t keep running into these problems.

I hope i’ve made clear that i am by no means a diesel mechanic, but doing my best to learn about my engine and get things sorted out to have a reliable vessel. i have rebuilt two stroke engines for fun, restored two center consoles and done some minor mechanic work but never been in a situation like this. i’m mechanically inclined, and extremely patient, but what i lack is the knowledge about my engine, which i’m seeking from you or anyone willing to help so that i do not continue to get ripped off. I have another boat to fish on so that’s really not the big deal. id be more happy knowing that i’m fixing my boat the correct way.

Again i’m not a mechanic. i’m a food salesman who enjoys working on my own equipment and knowing how to fix it so that if i run into problems offshore i know what the problem is. i read that my engine had an alternator driven tach, which has proven to be incorrect. again “lack of knowledge” on my end. which is exactly why i’m here. ideally i would have just paid a mechanic and all my problems would be solved, but that has proven to be a horrible idea.

Any help pointing me in the right direction is greatly appreciated. Any articles that you can direct me towards that would save me some time would be greatly appreciated. Any advice you have to give will be greatly appreciated.

Thanks.

[Tony Athens]

Look at the attached picture….You have one of these on your engine.. You need to get your tach working & calibrated.. That is “too basic”, and until you do that, and then looking at all the rest you need to deal with, you have a lot of work to do BEFORE you go fishing..

As I hope you now know unequivocally , you are spending $$ with the wrong people…..You need to find a good mechanic if cannot figure it out yourself..

And yes, ultimately, the grey wire runs the tach and it ends up at the mag pick-up.

Tony

[Maxime Barthe]

Tony,

The Tach stopped working suddenly about 4 months ago before the problem occured, not sure how. The only reason i believe the tach is alternator driven is i have 3 wires coming from the tach, one of them being a gray signal wire that i traced to the Tach (I did not remove the wire loom but it was the only gray wire) also today i just noticed that the orange wire from the alternator was disconnected with no sign of where it was originally connected. perhaps i’m incorrect!

[Tony Athens]

A hose in the sea strainer does just fine even it only supplies 1/4 of the water needed.. Remember, you are under no real load and all you have to do and keep the impeller WET..If water is dripping out the exhaust you are 100% safe impeller wise.

Are you sure you have an alternator driven tach? That would be really odd for this engine? Your tach is not working? Where / how did you get the RPM readings?

Tony

[Maxime Barthe]

Tony,

Thanks again for the response. I absolutely did read the low power trouble shooting article MANY times… my problem is i chose to trust a mechanic and this in turn screwed me (shame on me). The boat is on the trailer right now and i’ll order your intake system tonight. to my knowledge on the no dark smoke portion i followed all the instructions. All fuel lines were checked. Fuel solenoid was checked, all filters and lines leading to filters were checked. fuel pressure at the lift pump was checked and was also checked at the return check valve. throttle linkage was checked. after that

What would be a proper design for the exhaust? mine goes down and meets the fiberglass exhaust about a foot below the turbo. the flange were the water combines the exhaust wraps 360 around the exhaust port with a hole about every 1 inch. i’ll do my best to take some pictures when i take i disassemble it.

i don’t want to have anything end up the same way, again i stated that i would like for the boat to be extremely reliable as i take it for 200 mile 1 direction trips and back. I like to know that i’ll be able to trust my single engine boat. ill fix it correctly i just want to be absolutely sure because now i’m obliviously paranoid to spend more money on things that don’t fix my boat.

That is exactly why i’m here seeking the advice from you because you are probably the most knowledgeable person on this subject and i’m thankful for the time you’re taking to help me out!

i need to repair the Tachometer and i’m going to try to buy a phototach today. i believe i get tach signal from the alternator (which works) but i notice on my voltage gauge that its pulsing. would this have any adverse effects on my tach or is this just a bad connection, ive tried tracing the wire and cleaning the connections but still nothing.

One more question. i don’t have the adapter to run the boat out of the water so i disconnect the hose from the sea strainer and put my hose directly in. i only notice that my hose cannot supply enough water to keep the hose full, is this safe or am i risking destroying the impeller and sending pieces in to the tranny cooler. (i have an extra impeller just in case)

I will do as you say and follow your instructions to a T.

Thanks again

[Tony Athens]

Aftercooler servicing———-It needs to be done–Your Airsep has most likely been sending oil to it and the only way to know it to have it PROPERLY cleaned.. Ever tried to “breath” thru a straw?

You cannot use the Walker anymore – Look at the the built-in sink trap as to how it attempts to vent the engine………Dump it.

Exhaust –From what you describe, your exhaust needs to be redesigned- Your turbo did not do what it did internally from anything happening to it externally.. And if you fed it salt water thru the intake, that would not do anything to the exhaust outlet side. That would only help clog the aftercooler and ask your engines combustion chamber to see how much it likes to burn saltwater mist (plus add some sodium to the engine oil) .

$$ issues are fully understood–But why you even consider using the boat anymore only to see the turbo end up the same way?

TACH–Need to verify it’s reading in the 2000-2500 RPM range at the dock in neutral.. Then, we need to check NO-LOAD WOT RPM— Close to 3000 is the number we need to see) ..

Remove your belt guard until all is sorted out.. Plus, I am sure things that spin under need need full attention–all of them…………………………………….From there, we’ll address PROPPING… For this engine to give it all, it needs to see an easy 2700 RPM + loaded as to use the boat…………… My guess is it never has.

You need to start thinking “long term” and not worry about going fishing next week or next moth until all of this is sorted out.

CURIOUS–Have you read my article , and then followed it to the “T” on “low power trouble-shooting”? Actually, I guess that is a silly question as if you had, you would not have spent $5k for basically nothing …. … Remember, I am here to here to help, not make you spend $$ un-necessarily.. But still some has to be spent………….

Tony

[Maxime Barthe]

Tony,

Thank you so much for your help and fast answer. I just pulled the boat out of the water yesterday for the first time in 3 months to give her a good cleaning under the waterline (Surface drive/6 blade prop is difficult to properly clean in the water)

I did recently remove the exhaust elbow and coupler connecting to the exhaust branch and there was no water line in the exhaust system that far forward.

unfortunately the turbo has less than 10 minutes of run time on it so i’m not sure if taking a picture of the exhaust side will be able to help out much, but i will certainly do so when i put her back in the water next Friday after work. What i will say is that after looking reading and looking at the pictures of the turbo it certainly looked like the bad/rusty turbo with saltwater intrusion. my turbo was so rusty it was flaking on the outside and the inside looked bad.

before i jump into the new CCV filtration system (which i plan to do as soon as i get the power problem fixed)
my funds are pretty limited nor was i expecting to have to spend $5000 on fixing nothing. I do on the other hand still have $300 credit with SBMAR so perhaps that’ll be the first thing to get replaced

i will certainly go buy a phototach, are there any suggested brands?

the turbo was EXTREMELY rusty, i believe this to be due to the wet exhaust leaking onto the PTO shaft and being slung around the whole back side of the motor. not to mention the turbo could have potentially eaten some of the salt water on the compressor side which was pretty nasty. though truthfully it was fully functional.

My big issue is i was dealing with a mechanic who has truly shown me that he has no particular skill in diagnostics and was just replacing parts blindly hoping for positive results.

I understand the design of the center console does not lend its self to servicing the boat very easily. but its a bit too late for that and now i’m forced to work around it. WhiteWater boats have an outstanding reputation in South florida.. not sure what went wrong!

All criticism is humbly appreciated and i will not take any offense from someone who is far more knowledgeable then me on this subject, as the end goal is truthfully to have a good reliable boat again.

As for the JWAC, i’ll remove it and send it out, but out of curiosity does this have any direct effects with the power issue? is this a step we can bypass for now until i recoup a bit financially?

I want to point out that i’m on a pretty tight budget as i was not expecting to have to spend $5,000 nor was i really prepared to. Also i absolutely do not have another $5,000 to throw at the boat as of right now so i want to do as much as possible to figure out problems before throwing more money at it.

Thank you so much!

[Tony Athens]

6BTA 270 Low Power issues

#1———— You have gone about your troubling shooting 100% wrong.. So, if you want real help it will come from here and it will only work if you follow my lead without question. Also, you may not like some of what I say—Sorry.

First off, the builder of this vessel did not think much about engine servicing.. Things are really stuffed in there to where it’s hard to take care of things. With that said, the first thing you need to do is get things cleaned up and simplified. You need to start by removing the early style Walker AirSep and tossing it. It’s 100% backwards as to allowing the crankcase to breath properly.. Do some reading of this site about this particular engine and CCV’s.
Next, remove the JWAC on top on the engine and send it to a shop that has an ultrasonic cleaner to have it properly cleaned ( Dallas Coolers in Texas is a great resource for that). Do not take it to a typical radiator shop unless they understand and know this type of aftercooler.

Now, REMOVE the exhaust elbow.. Be sure the boat in in the water when you do this.. Why you ask?? I want to see TWO things.. I want to see inside the hose that it’s connect to—Do we see the water line in there? Next I want to see inside the exhaust outlet side of the turbo—–Refer to this article:

What a Marine Diesel Turbo should look like when Inspected

Do you own a photo tach? If not, buy one –Under $40.. I’ll teach you how to use it.

Things you need to ask yourself as we move forward—What did you need injectors at 500 Hours and why did you need a new or rebuild turbo too? Neither of these “wore out”..,,,,The answer to this will be related to what is going on..

Start with the above and let me know. And last—The pics on the forum—Send them to me direct in Hi-res.

Tony

[Tony Athens]

6BTA 270 Low Power issues

#1———— You have gone about your troubling shooting 100% wrong.. So, if you want real help it will come from here and it will only work if you follow my lead without question. Also, you may not like some of what I say—Sorry.

First off, the builder of this vessel did not think much about engine servicing.. Things are really stuffed in there to where it’s hard to take care of things. With that said, the first thing you need to do is get things cleaned up and simplified. You need to start by removing the early style Walker AirSep and tossing it. It’s 100% backwards as to allowing the crankcase to breath properly.. Do some reading of this site about this particular engine and CCV’s.
Next, remove the JWAC on top on the engine and send it to a shop that has an ultrasonic cleaner to have it properly cleaned ( Dallas Coolers in Texas is a great resource for that). Do not take it to a typical radiator shop unless they understand and know this type of aftercooler.

Now, REMOVE the exhaust elbow.. Be sure the boat in in the water when you do this.. Why you ask?? I want to see TWO things.. I want to see inside the hose that it’s connect to—Do we see the water line in there? Next I want to see inside the exhaust outlet side of the turbo—–Refer to this article:

What a Marine Diesel Turbo should look like when Inspected

Do you own a photo tach? If not, buy one –Under $40.. I’ll teach you how to use it.

Things you need to ask yourself as we move forward—What did you need injectors at 500 Hours and why did you need a new or rebuild turbo too? Neither of these “wore out”..,,,,The answer to this will be related to what is going on..

Start with the above and let me know. And last—The pics on the forum—Send them to me direct in Hi-res.

Tony

[Author]

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