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Reoccurring Engine Failure / Deisel Problem


Fish

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I dont like CAV filter housings - they leak, are very messy and slow to change if you have a blockage in a emergency.

 

Get a racor - much easier to change filters and no mess in the bilge - see Transdiesel

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Good thread this one. Learning heaps. Wheels, I get it why you would run your return line back to the filter. Makes sense. Does this make bleeding any harder though? Also, fuel tanks should never get a vacuum if the breather is OK.

Any photos of the Racor set up bubblegum? Never seen one.. Does it have a glass bowl so you can see water??

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If a CAV is done up correctly, they should not leak. Never had one leak yet.But yes, they are mesy to change because the filter element is also the body of the entire assembly, so to remove it you spill fuel.

Racor is a manufacturer of a range of proffesional Filters. From a small unit up to flamin great enormouse stuff. And all of them a real expensive. The smallest will be somewhere around the $600 mark I expect. Been awhile since I bought one.

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I bought a Racor filter assembly & element for may last yacht with a Yanmar 2GM20 diesel. I had the assembly fitted in July 09;

 

Racor Filter assembly - $237.77

10 micron filter assembly - $65.03

 

I had a CAV estimated at $90.00 for the assembly and $5.50 for the filter.

 

All prices included GST. I chose the more expensive Racor because it was easier for me to bleed if I ever had too. I have a CAV in my 1020 and even the diesel mechanics grumble about it.

 

As an FYI I also had a vacuum gauge fitted so as I could tell when the filter element needed changing. I don't have one of these on the 1020 (yet).

 

Oh and I have just been informed that I have water back in my 1020 tank :evil: I'm getting the O ring replaced on my filler cap even tho the original looked perfectly OK. After that who knows ..... condensation has been ruled out cause the tank it always full!

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Farrari, where does you breather pipe lead to?

 

(Interested because I haven't been down to the boat since this discussion started to trace my system).

 

Have to say, I'm looking forward to the day I have done some good hours under motor in hard conditions to get some confidence that she'll keep hammering away.

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Have to say, I'm looking forward to the day I have done some good hours under motor in hard conditions to get some confidence that she'll keep hammering away.

Ye olde marine diesel is a remarkably forgiving beast as long as it's receiving the basic necessities in a reasonably clean form. If it suddenly starts giving you grief, you know something has changed.

 

Knowing what to look for when that happens is a different story and I agree, this is a bloody good thread.

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Two suggestions:

 

1). Put a diesel fuel pump after filter but before engine.

Either an electrical fuel pump or a squeeze bulb (outboard type). Makes priming a lot quicker and easier.

 

2). Some filters have a small screw in plug in the bottom of the glass bowl. It is easy to bleed off any water & dirt into an icecream container, naturally emptied first :lol: .

 

Sorry I don't know which brand, but the extra cost of little plug could be well worth it. A lot simpler than undoing the whole filter assembly, especially in a seaway where all the dirt / bug / water is being stirred up.

 

It is a VERY good idea to mount the primary filter away from the drive belts and other moving parts :thumbup:

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It's a good idea to mount the filter in as easy to access position as possible. Along with the Oil dip stick, the oil cap, the water cap, the engine anodes, the saltwater pump impellor, the alternator belts, the watercooling belts, the gearbox dip stick, the gearbox filler cap, the......oh dear.

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I installed an electric pump after the filter.

It blew up as it didn't like suction I assume.

I installed another identical pump before the filter and it is going fine still.

The motor will run without it but the injector pump runs noisier without the electric one to pressurise the input to the injector pump.

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My Volvo had a little cam driven lift pump. It had a littlr lever for manual primimg. This was just before the injecytion pump. I thought all diesels had something like this?

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Nah, that's long gone from mine. There is a plate across where it fits.

To bleed mine after changing filters etc I just turn on the ignition for 5 minutes to circulate the diesel and it fires first time.

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On all the more common engines, there is a mechanical lift pump. The very latest "common rail" engines don't. Volvo and a small number of some Ford engines have a a "plunger" type pump. These pumps tend to be a littel more reliable than the diaphragm pumps. The diaphragm pumps are driven usually by the cam shaft. The problem with those is that the Daiphragm can eventually fail and leak fuel into the sump. Although only in a small amount. But if you fit an electric pump to the system, it pushes a lot of fuel into the sump. So it is best to by pass the mechanical pump if you are fitting the electric.

Inside the mechanical Pump is a small fine mesh filter screen. Take the cover off the pump and remove the filter and deep six it. It can block and it is not easy to get at and often not even known or remembered it is there. You should always have two replacable filters. One before the pump and one after the pump is best. the one before shopuld normally be a 10u filter with a water trap to monitor water and catch most rubbish. The filter after should be a 2 - 5u and the CAV filters are most commonly used here. Often these ones don't have a glass bowl, it doesn't matter. But these ones wil filter anything that manages to get through the first filter.

My set up has a large Racor then the mechanical lift pump and then two smaller CAV filters. I carry spare filters on board for them all.

 

Smithy...no bleeding is just the same with return at input to filter.

 

I really don't know where the idea of returning to the tank ever came from. It always seems so complex to me.The only engine that we would normally see (as in not huge) would be a Detriot and I don't know of one on a yacht anyway. But they return a high volume of fuel to tank for cooling of the pump and you can not return the fuel back to the line. It is too big a flow and too hot so has to return to tank.

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Can you get 10 micron elements for the Cav units?

I have a glass bowl one after the electric pump, then the factory one without glass bowl fitted on the engine.

They both have the same element in, so it is belt/braces territory. If I could get a 10 m filter I could put it after the electric pump to protect the pump from any buildup.

As I said before, the electric pump didn't like sucking through the 3 micron filter.

My mechanical pump was driven off the injector pump. I have a rebuild kit for it still though. :D

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Nah, that's long gone from mine. There is a plate across where it fits.

To bleed mine after changing filters etc I just turn on the ignition for 5 minutes to circulate the diesel and it fires first time.

So you must have an electric pump somewhere?

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Alrighty,

The deisel tank is now sitting in the middle of the owners front lawn. It only took about an hour to get the tank out, unfortunately it took a good day to dissassemble the port quater birth - the boat now looks like George Bush thought there was oil on it :? :?

 

There is shite clearly evident in the tank, brown shite particularly in the corners etc. About a cup of diesel is still in the bottom, this is cloudy with floaties...

 

We were going to go to work with a water blaster and hot / sterilising water etc to clean the tank via the current openings. The general consensus is the only way to clean the tank properly is to cut hatches in the top so it can be cleaned / scrubbed by hand? This will be additional cost and shagging around but we are gettingthe impression its the only way to do the job properly? The current opens are max 2in diameter x3.

 

The breather was restircted but not blocked. I'm going to replace it anyway, especially while I can preety much walk around back there.

 

We've also replaced the O ring on the filler cap.

 

We have a CAV filter pre pump and another filter post pump. I don't know what micron they are as the owner spec's thoses, but we will replace them all again so will find out.

 

Will investigate moving the return line direct to the filter rather than the tank. Its a 120l tank so I'm not very keen on keeping it full all the time to prevent condensation. Partly because of weight but mainly because of the time it would take for us to get through 120l. We use 3l/hr so we're talking about a very slow turnover at those volumes.

 

What are the recommendatiosn to prevent a re-occurance? Use the good deisel additive and shift the return line?

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Its a 120l tank so I'm not very keen on keeping it full all the time to prevent condensation. Partly because of weight but mainly because of the time it would take for us to get through 120l. We use 3l/hr so we're talking about a very slow turnover at those volumes.

A bit out of left field Fish, but if you have a tank that:

a) needs a major cleanout and

B) is so big that you are reluctant to keep it full and the fuel spends a long time in there

 

have you priced up a new, smaller tank?

 

Think there are some plastic versions around these days too, don't know anything about how durable they are but gotta be lighter.

 

Here's one option from the dim dark memory bank - apologies if I have overlooked any Kiwi manufacturers:

http://www.leisureshopdirect.com/Marine ... _Fuel.aspx

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I've thought about getting a new smaller plastic tank, but haven't investigated it yet. It was primarily on a cost basis. We got some stupid quotes to clean out our current tank, in the order of $1,500, in which case I would think it cheaper to replace the tank than have it cleaned. Hence we've gone down the track of removing it ourselves.

 

You're right though Murky, its worth investigating I think.

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At that kind of money, this joker could be worth a try as well and you could have pretty much any size/shape you want:

http://www.herculestanks.co.nz/boat_tanks.htm

 

You could still hang on to the stainless one for any future extended cruising etc but it sounds like for the way you are using the boat most of the time, smaller might work better.

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