[JimmyK]

Those are some ugly pictures!  Lots of saltwater around the intake while underway (looks like even the air filter is covered in rust?!) and the color of the paint on the turbo intake side also speaks volumes.

[JimmyK]

No idea why you’d check your fuel filters w/black smoke, but the air filter isn’t a bad idea.<br /><br />Better than that, navigate to the low power troubleshooting guide on this site and go through it step by step.

[JimmyK]

No problem, but reading your original post, if you have black smoke while the engine’s trying to spool up, you DO NOT have a lazy aneroid, and reducing aneroid preload is going to do nothing more than give you more black smoke.  You’re barking up the wrong tree IMO.

1 user thanked author for this post.

Tony Athens

[JimmyK]

There is torx, and there is also torx plus.  There are also 5 and 6 point versions of each, then there is also the tamper proof variant (same as security).  You have to get them all right.

What Dan posts is a hex or allen drive, totally different, doesn’t apply.  Torx also is not metric or standard.

The screw you’re trying to take off is a tamper proof 5 point torx plus drive, size 25.

With that said, every time I’ve tried, I just shear the tip of the bit off.  That screw is usually on there pretty good and the hole in the middle of the bit (tamper proof feature) makes the bit really weak.  I just grind flats on the screw and remove with vice grips.  It isn’t holding anything on anyway, just there so you don’t ‘accidentally’ adjust the aneroid preload.

[JimmyK]

My experience w/the 160 t-stats in 6bta 370s was meh.  Yes, it ran cooler, but too cool at idle/trolling speeds.  They start opening close to 140 which is just too low.  Maybe I got a couple odd balls but they were both exactly the same.

Keep the cooling system up to snuff, have an alarm that works, and pay attention.

[JimmyK]

Color of smoke?  Check your coolant level.  One possibility: turbo gasket is easy to install 90° out, will dump coolant in exhaust and give white smoke.

[JimmyK]

Sounds like a bad ground connection to me.

[JimmyK]

I would say it’s prudent to expect an owner trying to sell you a boat is not going to tell you that an engine has low compression unless it needs a rebuild.  That’s what I would budget and negotiate into the price anyway.  If you end up buying it then you can do more sophisticated troubleshooting to see if a full rebuild can be avoided, but go ahead and expect that the engine has to come up and undergo a top to bottom rebuild, with the hope that there is some upside once you own it.  6B being a parent bore engine and re-mans being a good value, many just opt for the re-man long block as opposed to over boring and rebuilding.

Good luck.

[JimmyK]

To me a ‘bendix’ has come to mean the ‘thingy’ that causes the starter pinion to engage.  These days (for a long long time), this ‘thingy’ has been electrically (solenoid) driven and typically includes an electrical contactor to send juice to the starter motor, ensuring that the pinion is engaged before the motor spins.

Why is it referred to as a ‘bendix’, well that’s sort of like why we call all adhesive bandages ‘Band-Aids’, even when they’re not band-aid brand.  Another example is when we refer to hook & loop fasteners as ‘velcro’ even when the Velcro company doesn’t make it, and even though the Velcro company makes more than just hook & loop fasteners.  Just a colloquialism that a lot of people use, but apparently not enough people to avoid confusion.  Semantics, that’s all.

We all agree w/the answer that he should add a mag switch (itself a colloquialism for an electrical contactor, relay, etc 😉

 

[JimmyK]

The mag switch activates the bendix on the starter and the bendix activates the actual starter motor.  The mag switch is the go-between for the ignition switch and the bendix.  If you have an ignition switch rated for the electrical load of the bendix (doubtful) then you don’t need one, otherwise you need to add one.

[JimmyK]

Yes, the stock hoses that connected the raw water pump to the fuel cooler and the fuel cooler to the aftercooler were molded.  They were molded for 2 reasons…they are short with a significant bend and they were connecting nipples of different diameters.  Buying a corrugated hose might be enough to get them to bend without kinking, but will not address the different diameter challenge.

Your two realistic choices are to replace with new molded hoses or eliminate the fuel cooler as described above.  Also as mentioned above the molded hoses are weak links any should be inspected regularly with the engine at full rpm.  I lost one of these hoses 60 miles offshore.  Checked the other side and at idle it looked fine but when the rpms were raised they blew up like ticks.  Heat, age, pressure cycling do a number on them and they turn into balloons until they go pop.

[JimmyK]

I see Gene’s point and it is valid.  The engines have nothing to do with speed at a given rpm.  That is a function of the gear ratio, props, and boat (bottom design, weight, etc), but not engine (aside from engine weight).  You have to understand and accept that before going any further.  The engine can dictate what rpm can be reached but not the speed achieved at that rpm.

With that said, it seems clear you have two problems compared to your friend’s boat. 

One is what Gene describes–there is at least one significant difference between your boat and your friend’s boat totally outside the engines.  Props are different, but are yours that much less efficient?  Doubtful IMO.  Weight would be number 1 suspect.  Some boats are like some people and have a habit of gaining weight.

On the other hand, it seems clear to me that you also have something going on with the motors.  They are likely not making full power.  I would start by trying to figure out why they will not reach rated RPM in neutral.  This has nothing to do with the aneroid or turbo.  As said above, number one suspect would be something going on with the injection pump.

[JimmyK]

You’re describe high blow-by symptoms, tech who has his hands on says it needs a rebuild.  Compression varying 20% from low to high.  With info given, sounds like tech might be on to something.

If you think he’s wrong, measure blow-by per the procedure on this site, post numbers.  Also pull off your exhaust elbow and take a good picture of the exhaust side of your turbo.  Post pics of that and your exhaust set up. 

What is the WOT rpm underway?  When is the last time the aftercooler has been fully serviced?  Heat exchanger?  Raw water pump?

My guess is you have a lot of bad things going on from lack of maintenance, and the tech is right, but you haven’t provided a lot of info.

[JimmyK]

Amazing that the engine was still able to make rated RPM w/no ill signs.  I would bet the coolant leak is a separate problem.  Take a look at the head gasket.  Typically these engines first leak from coolant passage to outside, not to the combustion chamber, near #1 cylinder.

[JimmyK]

I bet they just plain screwed up the test.

Re-install once it is rebuilt and add the temp probe and de-rate to 75% using the belt manager and I think you’ll be good.

[JimmyK]

Agree, shut the fuel off.

And while the last chance filter comes after the lift pump, it is a good idea to clean around the old valve with a little solvent (like IPA) to keep stuff out of the fuel system.

[JimmyK]

My best guess is you have the worst type of problem–an intermittent one.  Personally I would put the alternator back in the way it was and re-test it as a next step.  I’d honestly hope that it didn’t work (again) so I could spend more time troubleshooting.  However, my guess is that it will indeed work fine, leaving you to wonder what the root cause was and when it will return.

I say this because based on your test results and methodology I would have guessed bad alternator, but based on the shop’s testing, I would now change that to intermittent alternator (sticking brushes, possible bad connections, etc?).

It could also be something with your test methodology was off that isn’t coming through with your description.  I’m not trying to nitpick but I would have full-field tested the alternator in situ before removing it to confirm it was bad.  It doesn’t sound like you need the warning, but ensure you do not have the alternator connected to the boat’s electrical system when full-field testing.

[JimmyK]

It is conceivable that the primer pump started leaking after the filter change, especially if you used the pump to prime any part of the system. The bad news is that those pumps aren’t well made.  The good news is that their cheap price reflects that and they’re easy to change.  I was thinking I would take mine apart and fix whatever was wrong with it (likely an o-ring) until I saw the price of a new unit (<$20 on Amazon)

Note that this isn’t necessarily your problem, but if it is leaking then I’d definitely replace it and see if you can kill two birds with one stone.

It won’t let me post an Amazon link but search OEM DIESEL HAND PRIMER PUMP 2-447-222-125

1 user thanked author for this post.

Tim

[JimmyK]

How did you measure the field current?  Did you actually measure the output voltage at the alternator?

Balmar has a very good step by step troubleshooting guide.  I suggest you download it and follow it step by step.

[JimmyK]

Yes, what I wrote is the same as what I see in your quote.  Note that they refer to the condition that will initiate the field reduction as a ‘catastrophic over-temperature condition…’

This is markedly different than what is implemented in the MC-618 which uses the alternator temperature as an input to the PID controller to proactively maintain the alternator at a safe temperature before there is an over-temperature condition.

Said a different way, the ARS-5 includes alternator temperature sensing as a means to react to a failure or fault state.  The MC-618 includes alternator temperature sensing as a means to proactively control alternator temperature at or below a preset point.

If you’re going to keep the ARS-5 for $$ reasons (totally get it), I would add the temp sensor for sure, but also adjust the belt-load manager setting to reduce the maximum output of the alternator.  I have found most alternators can sustain about 75% of max output without frying themselves, so something at or below this threshold should increase alternator life substantially, although it is alternator and install dependent.

[Author]

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