[C320-list] Yanmar Question -Assumed Fuel Injection Limiter Leak

mike hunter popotladreaming at yahoo.com
Tue Aug 25 08:01:09 PDT 2009

Thank you, Robert!  :)

From: Robert E. Sloat <resloat at comcast.net>
To: C320-List at Catalina320.com
Sent: Friday, August 21, 2009 9:36:55 AM
Subject: Re: [C320-list] Yanmar Question -Assumed Fuel Injection Limiter Leak

Mike-I don't think it is a pressure relief valve.  I am away from my 320 with the same
engine and only have the factory service manual to work with.  The factory
service manual shows are two caps right next to each other. It looks like
each has wires either to the cap or to the lock nut below the cap. One of the caps
is on the top and points up and one sticks out horizontally pointing forward. The threaded shaft underneath each of these cap nuts is preset at the factory and locked in place with the lock nuts underneath the cap nut. The wires are used to keep them from being changed unintentionally.

The one on the top is the no-load maximum speed limiter which is set at the
factory during bench testing and looks like it limits the regulator lever
below it.  It is not clear if this cap connects to any part of the fuel pump where fuel may be.

The one sticking out pointing forward is the fuel injector limiter.

Per my service manual at pages 4-2, 9 and 11, the one pointing forward has a
seal washer between the cap nut and a lock nut and a seal washer between the
lock nut and the injector pump body or engine block.  I assume that one is
leaking as there are sealing washers used.

> From the drawings, you can tighten the sealing washer between the cap nut 
and the lock nut by
putting a wrench on the lock nut, holding it in place and tightening the cap nut.  If the cap nut is not
tightened on the seal  then I would think this would stop fuel leakage.

Be careful as underneath this cap is a shaft that you use to adjust fuel
metering and things get very complicated if this is misadjusted. If the lock
nut is loose, you should tighten it after taking off the cap nut while
preventing the shaft it is attached to from turning.

Hopefully this helps.

Bob Sloat
Savannah Hull 894

----- Original Message ----- From: "mike hunter" <popotladreaming at yahoo.com>
To: "C320-List" <c320-list at catalina320.org>
Sent: Thursday, August 20, 2009 7:03 PM
Subject: [C320-list] Yanmar Question

Question for the Yanmar gurus:

There is a wire tied threaded cap to the left of the injector pump on my
3GM30F that is loose and leaking a little fuel. The wire is preventing the
cap/nut from loosening further. Before I tighten it I was hoping to get some
information on the purpose of this cap and why is it tied off with wire? Is
it some type of pressure relief valve/vent?

Thank you!


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