[C320-list] Fuel Tank Access Port

[Larry Frank]

David,

I have a 1995 320 and did replace the fuel tank a few years ago after it began leaking so I agree with all the advice here.  However you did not say what you do to get Adelante running again.  Do you know you have a plugged fuel filter.  Water in the bottom section of the filter?  I ask these questions  because there I another problem that can occur and it displays the same symptoms as you describe.  It is possible that air is leaking into the fuel prior to the fuel lift pump.  In this part of the fuel system the fuel is actually under a vacuum which is how it gets sucked from the tank in the first place.  Air can get sucked in too.  I will add my story to illustrate what can happen.

I began having problems with WindSwept which is a 1995 around 2005.  What would happen is that I would motor for an hour or two and the engine would surge and usually stall.    After a few minutes I could get it restarted and baby it back to the slip or anchorage.  Then I would change the fuel filter and everything seemed fine.  That is until I motored 2-4 more hours when it stalled again.   I went the route of renting a fuel polisher and trying that.  Did not solve the problem.  Boy was I getting fast at changing fuel filters - that were probably perfectly ok.  I even dissected a filter and it did not look dirty.  I then got the idea of an air leak and I substituted the fuel return from the high pressure pump back to the fuel tank with a clear hose and holy cow there were air bubbles.  Now that I knew what the problem was I started just pumping a little fuel through the filter with the priming pump and the engine would run well for another 2-4 hours.  I got real good at this too.  I never could find the air leak and after eliminating everything else had a brand new fuel filter housing installed.  Didn't fix the problem.  I was really getting frustrated and this charade went on for a couple of years.

Finally the fuel tank developed a leak and had to be replaced.  Immediately the problem with the air leak went away and the engine ran perfectly fine.  The conclusion was the dip tube in the tank had a pinhole leak at the top of the tank and was the source of the air.

I would never argue against replacing the fuel tank on a mature 320 as the new ones are manufactured with thicker aluminum and sooner or later you will need to do this.  But you might want to discuss the symptoms with your mechanic and bring up the idea that the problem may be an air leak.

Larry
WindSwept C320 #246



On 4/21/20, 1:04 PM, "C320-list on behalf of David Veeneman" <c320-list-bounces at lists.catalina320.com on behalf of davidv at veeneman.com> wrote:

    I have had recurring engine problems since I bought my boat last year. The engine will run fine, but after a day of sailing through choppy waters, it dies. I’m guessing that there is a pretty good layer of muck at the bottom of the tank. The boat sat in a slip for ten years before I bought it, so that wouldn’t surprise me.
    
    My mechanic tells me the 320 doesn’t have an access port on the fuel tank, so cleaning may be problematic. I am looking at cutting an access hatch in the tank and installing a Seabuilt Tank Access Plate (http://www.seabuilt.com <http://www.seabuilt.com/>). I’m going down to the boat later today to have a good look at the fuel tank. Hopefully, it has a flat top on which an access port can be cut.
    
    I’m hoping folks can help me with these questions:
    
    Can the fuel tank be cleaned through the sending port?
    Does anyone have experience with Seabuilt access panels?
    Is the C320 fuel tank baffled, and are the baffles solid?
    
    Any other advice regarding this problem? Thanks for your help.
    
    --
    David Veeneman
    Dana Point, CA
    SV Adelante, C320 #131