[C320-list] Edson pedestal throttle problem

[Jack Fitzgibbon]

There is technical information on the 320 web page that may help correct your situation.  Unfortunately I can't relocate the article.  We used it not to long ago it to fix a problem we had with our throttle lever slipping and not holding a selected position. We had to physically hold the throttle open to add RPM to the engine.  Once released the throttle would return to an idle setting.   Apparently, over time, the throttle lever gradually moves from its normal configuration and has to be readjusted.  

This is the method I recall using to make the repair.  The throttle lever arm enters the inside of the binnacle housing and is located directly under the compass.  To get to the throttle linkage you must remove the compass. There are two screws that hold the collar around the compass at the light fixture.  Once the collar is removed you can access the 4 compass mounting screws that also need to be removed so you can lift the compass from it's installed location.  The compass light fixture electrical power cord is routed around the lower section of the compass and was long enough that I could set the compass down on the port cockpit cushion with a towel situated around the perimeter of the compass so it wouldn't roll of the seat. 

The throttle linkage is clearly visible.  In our case there was a hex head set screw/bolt threaded into a collar around the throttle arm.  I loosened the bolt and the throttle re-seated itself in the full aft position.  I retightened the set screw/bolt making sure not to over tighten the set screw as the collar body is aluminum and over torquing the steel screw/bolt could strip the threads in the collar. It was recommended to use loctite as an added locking feature to prevent the problem from reoccurring.  Re-assemble in reverse order.  

The next time we went for a sail we found the throttle operated normally.  I don't know if this will solve your problem but it may be worth the trouble shooting effort to try it first before attempting a more complex or expensive solution. 

Jack
S/V Wetted Bliss
#441   
       



-----Original Message-----
From: c320-list-bounces at lists.catalina320.com
[mailto:c320-list-bounces at lists.catalina320.com]On Behalf Of Scott
Thompson
Sent: Tuesday, September 30, 2008 12:19 PM
To: C320-List at Catalina320.com
Subject: [C320-list] Edson pedestal throttle problem


When I started Surprise's engine yesterday I noticed that she was idling
rather fast.  When I tried moving the throttle lever it was stiffer than
usual and the motion was rough and jerky as if something was hanging up. 
When I opened the engine cover it was clear that the throttle cable was
not pushing the throttle lever on the engine all the way to its idle stop,
explaining why the idle was fast.  (I was able to pull the lever on the
engine to the full idle position manually, so the problem is definitely in
the linkage, and not the engine itself.)  All connections at the engine
end were tight so I assume that nothing slipped there.  Back on deck I
disassembled the binnacle only to find that the push rod connecting to the
throttle lever connects to something deep below the throttle lever itself.
 This connection is not visible from above.
I removed the cover from the steering pedestal mounting in the aft cabin
and determined that the transition from throttle lever to red-jacketed
push-pull cable is above decks, in the pedestal itself.  Does anyone know
how I get access to that end of the cable?  Short of disassembling the
entire steering system and binnacle/pedestal I hope.

Is there a blow up diagram of the pedestal somewhere that might help me
figure out what is going on?  Does anyone know the specific model number
used by Catalina on a 1999 C320?

I'm guessing that the mounting of the cable inside the pedestal has
vibrated loose.  (Probably because of all the vibration I've been getting
from my Gori two-blade folding prop, but that's another story.)

Also, my recollection is that there was a thread on this list a few years
ago about problems with the bolts securing the top of the binnacle siezing
in the aluminum.  I have that problem with one of the bolts.  My
recollection there was a fix involving replacement bolts of another
material available from Edson, and this has been on my mental "to do" list
for the last few years.  Does anyone have the specifics?

Finally, the clamp ring on my compass would not tighten when I reinstalled
it.  I think the threads are stripped on the little brass square that the
bolt tightens into.  So I will need some replacement parts for this as
well.  Does anyone know the model number for the compass?  I forgot to
write this down when I had it apart.

Scott Thompson
Surprise, #653