[C320-list] Attention early 320 owners with Westerbeke Engines - Check your on-engine throttle linkage that may fail due to vibration or use causing linkage bolts/nuts loosen resulting in dangerous conditions

[Rick Sulewski]

Westerbeke model owners,

I started my boat before leaving the dock and found my throttle linkage
failed just before placing the transmission in gear. Upon pulling the front
engine cover I learned that one of the throttle attachment bolts that was
installed so the nut is on top of the linkage arm  was missing the nut
causing the bolt to drop below the top lever arm. There are two linkage
levers that are attached by two bolts & two nuts so that both levers
function as one unit where the throttle cable is attached. The cable
attachment may then two throttle levers bolted together to open/close the
throttle (look for the bolts/nuts visible where the throttle stop is located
on the front starboard side of the engine). Both bolts on my engine were
installed with the nuts on top but I found that if the most outboard bolt is
reversed, then the nut may become loose or even detach, but that particular
bolt would be captured by the top of the bolt cap. However, the second bolt
must he installed with the nut on top because of a lack of clearance. The
second bolt's nut was loose and allowed the linkage with the dropped bolt
(missing the nut) to rotate around the second bolt  causing loss of throttle
control. If this loss of throttle control condition occurs while the
throttle is opened at higher RPM speeds, then it would be necessary to
either disengage the transmission or pull the engine stop T-handle and kill
the engine. Since I was about to leave a busy transient pier, I was lucky
the linkage bolt dropped before I engaged the transmission and throttled up
to leave the crowded pier.

 

My remedy was to locate the missing nut, tighten each throttle bolt & nut,
and then attach some large zip ties between the two bolts and over the nuts
to reduce the likelihood that I may lose the bolts/nuts while also having
the zip ties holding the two lever arms together. I did install the outboard
bolt so the nut is at the bottom of the linkage lever so that bolt cannot
drop down causing a loss of throttle control. However, be aware that if the
second linkage bolt were to lose its nut and drop down the linkage may jam
causing the throttle to jam in either a low rpm or very high RPM
condition...consider how often we rely on a burst of engine speed and what
could take place if throttle control was lost under a throttle burst.

 

Hope this message is clear enough to cause Westerbeke model owners to check
their throttle linkage. I have 1,200 hours on my engine.

 

Rick

My-Ria 1995 320 hull #277