[C320-list] Fuel Filter

[Scott Thompson]

I think the situation is more complicated than that, since there are 
T-connectors in the fuel lines involved.  I confess to never 
understanding the purpose, design or logic of the fuel return system.

That said, I recall that there is a different, low-tech fix for this 
problem that involves putting a ball bearing in one of the fuel lines to 
block flow.  An experienced Yanmar mechanic recommended this to me a few 
years back, as a preventive measure.  Since I wasn't having fuel 
problems I didn't do the fix then, didn't write down the details, and 
now can't remember them.  Does anyone else remember the details?  I'm 
pretty sure I read about it here first, long before the mechanic made 
the recommendation.

Scott


bruceheyman at cox.net wrote:
> Chris,
> Check valves, being mechanical are prone to failure and the usual failure mode is that they leak in the direction they are supposed to check.
> I'm assuming that the fuel return is to the top of the tank and hence it is exposed to air within the tank.  If the check valve fails in the open position then it will allow air into the line and the fuel will drain into the tank.  However in this case if you simply removed the check valve then it would seem you would always allow air into the line.
> Feels like the best solution would be a return fuel line plumbed to the bottom of the tank and no check valve.
> Bruce
> Somerset 671 SoCal
> Sent via BlackBerry by AT&T
> 
> -----Original Message-----
> From: Chris Burti <clburti at gmail.com>
> Date: Sat, 19 Jun 2010 21:05:26 
> To: <C320-List at catalina320.com>
> Subject: Re: [C320-list] Fuel Filter
> 
> That was the recommendation from Yanmar, or possibly Catalina or Mack
> Boring...I do not remember for sure now, but I am sure that it was an
> authoritative source.
> 
> There was an old thread before we moved the Association server and I am not
> sure if it can be found in the archives...apparently the check valve is not
> required for the return to operate adequately and there is one school of
> thought (of which I am included) that check valves are a failure waiting to
> happen and usually at the worst time, so I don't use them if I can avoid it.
> I do have one in the sump outlet line in my basement, but the pump has to
> lift the water over 10', so it is a necessity.
> 
> Other than a clogged fuel filter, there are only two things that I am aware
> of that will cause this symptom to exhibit. The check valve is one and the
> other is a damaged crush washer on the bleed screw  just before the
> injectors. If the bleed screw is over tightened, the crush washer will
> flatten and allow a small air leak.
> 
> I have seen reports of bleeding and then the problem recurring and finally
> tracking the problem down to one or both of these issues. In all honesty, I
> have yet to try to correct either possible issue, because a couple of
> strokes on the priming pump on the Racor seems to eliminate the issue until
> the next time. Since I have to open the intake anyway it has become part of
> my start up routine when we board the boat after an extended absence.
> 
> 
> 
> On Sat, Jun 19, 2010 at 10:33 AM, <bruceheyman at cox.net> wrote:
> 
>>  Chris,
>> First I've heard of this but it would explain why the boat can be hard to
>> keep running when we first start it up after a month of not using it.  Why
>> are you recommending removing it verses repairing it?
>> Thanks,
>> Bruce
>> Somerset 671 SoCal
>> Sent via BlackBerry by AT&T
>>
>> -----Original Message-----
>> From: Chris Burti <clburti at gmail.com>
>> Date: Fri, 18 Jun 2010 16:27:54
>> To: <C320-List at catalina320.com>
>> Subject: Re: [C320-list] Fuel Filter
>>
>> Changing the fuel filter is a good idea.
>>
>> There is also a recurring problem with the fuel systems in our generation
>> of
>> boats. There is a check valve in the fuel return to the tank. If and when
>> this valve fails, it permits air to work back up the return to the
>> injectors. The check valve should be removed. Until it is, you can run a
>> few
>> strokes on the lift pump in the Racor filter separator and it will solve
>> the
>> problem until the engine goes without for a few weeks.
>>
>> On Fri, Jun 18, 2010 at 2:09 PM, Joseph Aberdale <summerwind3 at comcast.net
>>> wrote:
>>> My Yanmar engine 3GM30F in my 2002 Catalina died while underway.  I'm
>> going
>>> to change the fuel filter to determine if that's the problem. Is there a
>>> fuel shut off valve I need to close before changing the filter and where
>> is
>>> it located?  How does the filter housing come apart to change the filter?
>>>
>>> Thanks very much in advance for your help. It's appreciated.
>>>
>>> Joe
>>>
>>> #908
>>>
>>
>>
>> --
>> Chris Burti Farmville, NC
>>
> 
> 
> 

-- 
Scott Thompson
Surprise, #653