Stuck fuel shutoff switch

[Braxton]

Yesterday was easily the best day of sailing that we've had since we got our boat.   Unfortunately the day was marred by a non starting engine when we were ready to come back in.   Ultimately the culprit turned out to be the engine kill/fuel shutoff switch on the engine (M-25XP).    Its stiff enough that it takes a pair of vice grips and a long screw driver user as a lever to budge it.   

Does anyone have any experience working on these things.   My thought was that taking it off, cleaning it up, and lubing it will put it back to normal.  But I'd love to learn from everyone else's experience before I dive in there myself.    I haven't done any exploratory surgery yet so I'm not completely sure how it goes together, any pointers there would also be appreciated.

Thanks in advance :)

-Braxton Allport
-Ballou '88 #805

[Stu Jackson]

Have you checked the engine manual yet?  I have a writeup by a fellow C34 skipper, Jim MacNeil, who doesn't do computers, so I'll type it out and post it later.  He says: easy removal, four small screws on the side of the engine, lubricate.

[Braxton]

While my engine manual has many more greasy finger prints on it then it did yesterday morning I did not see anything relating to this switch.   If I missed it please feel free to give me a virtual slap upside the head.

Presumably when I do this I need to have the fuel shut off at the tank and I'll have to bleed the system after wards.  If its really as easy as four screws it doesn't seem as if it will be all that bad.

I'll try and take some pictures as I go to better share my experiences.

[Ken Juul]

9 chances out of 10 it is the shutoff cable that is the problem.  Easy way to test is to disconnect the cable at the engine end and check the movement in the shut off arm.  It should move easily.  While you are disconnecting the cable, take a good look at the exposed end.  If it is frayed or has fishhooks (use tissue not your finger to check) then the cable should be replaced.  If you determine it is the cable, and the engine end looks ok, then the most likely spot for corrosion etc is at the cockpit end where it is exposed to the elements.  Start liberal applications of PB Blaster or similiar bolt loosener.  WD 40 is a moisture dispersant, so not the best in this application.  Work the cable up and down until free movement is restored, then lube with a good liquid lubricant, apply several applications so it works it's way down the cable run.  Be carefull not to pull the engine end of cable into the cable run, might have a hard time getting it back out.

In step one if you determine it is an engine problem, don't forget we have engine manuals and parts break outs in the manual section of the home page.  Stu is correct, disconnect the cable and 4 bolts later the assembly can be removed.  It is up front on the engine so access should not be a problem. As a general principle I would replace the gasket, either get one from you local Kubota dealer or make a new one from light cardboard. As you dissassemble it, you should be looking for a reason for the problem.  Do/did you have a water leak dripping on it leading to corrosion?  It should be internally lubed, probably splash or spray from an internal oil port, does it have an oil film on the internal pieces? Etc.  

It is a good idea to shut off the fuel, I usually use a padded vice grips on the rubber fuel line just before the Racor rather than unload the cockpit locker to reach the shut off valve.  Some bleeding may be required, when you get it back together open the bleed valve shown on Page 19 of the Universal manual and turn on the key, the electric pump should take care of it in a minute or two.  The parts breakdown in the manual section of the home page has a good diagram, if I remember correctly it is section 10.

This is the first time I can remember hearing of this problem. Please report back on your findings.  Take lots of pictures and consider writing an article for the Tech notes section of the Mainsheet.

[Braxton]

The switch/valve on the engine is the culprit.   The cable moves just fine.   

By the gasket do you mean part #23 from this diagram?

http://www.marinedieseldirect.com/catalogs/catalog_group.php?owner=mdd&catalog=200142&model=M-25%20/%20M-25XP&page_ident=200142-21&manufacturer=Universal&title=Engine%20Stop%20Lever%20Group&size=600

Good suggestion there, I imagine I'll destroy it trying to get the 20 year old assembly apart.

And yes, I do have a water leak, I happened to discover it yesterday while troubleshooting this issue.   I have a nice stream of water coming our of the raw water pump.   It doesn't look as if it would be the culprit as its spray is going in the opposite direction but you never know how things can get redirected while the cover is on.   I pulled the raw water pump apart about a month ago to inspect the impeller, the leak probably started then.    Its slated to get fixed at the same time so it should cease to be an issue.

[Braxton]

BTW:  is this a worthwhile purchase?

http://shop.torresen.com/marine_diesel_direct/Universal/index.php?p=details&mfc=Universal&sku=200155

I've seen tech manuals that are worth their weight in gold and others that are useless.   Where does this one fall in the scale?

[Ken Juul]

Yes, #23 is the gasket in question.  From the diagram it appears to be cork.  Heavy cardboard or gasket material can be substituted.

We don't have that exact manual, but one that is close enough in the manual section of the home page.  And I have a paper copy on the boat, happy to fax/scan specific pages if needed, however there will be a time delay as I can only get it on the weekend.  Hopefully your engine repairs will be minimal, it is probably not a required expense.

Water leaks are evil, especially in a salt water environment.  They cause untold problems and should be fixed immediately.  As you wrap up your repairs give all the electrical connections a good shot or WD 40 or CRC to prevent future corrosion.  Good luck in your repairs.

[Braxton]

I have the regular manual that matches what's up on the website.   I was looking for a more comprehensive shop manual for the engine.

They frequently have detailed instructions for how to do things like this.   Especially tricky assemblies, for example I'm worried about the spring assembly inside of the valve.    (Parts #16 & #18 in the diagram).   If I have to pull that it could be a real pain getting it back inside correctly, especially since I don't think I'll be able to get my head around to look into the part.   (It may be time to add a dental mirror to the tool kit).

I actually went ahead and ordered the manual and both gaskets (water pump and fuel shutoff).   Hopefully I'm not getting a duplicate of what I already have.

[Stu Jackson]

From Jim MacNeil [Dec. 2007] Hull #1040

"Here is a maintenance item for the C34.  I could not get a start after winterizing.  I mean it did not sound like it would ever start!.  Turned over but no kicks or anything.  I talked to an engine mechanic who advised that it was probably in the shut off system where you pull the handle up and shut off by returning the handle to its original position.  The mechanism for this action is under a plate on the side of the engine.  Remove four small screws, remove the plate.  He said to lubricate with WD40.  I don't know if that is the proper lube - I would think a heavier grease would be long lasting. Anyway, it started up fine when the plate was replaced.  My son really did the job.  I gave him the info the mech gave me.  It sounds like something that could be a problem but turns out to be a simple solution." 

Braxton, I got this about a year ago and its been sitting on my desk waiting for someone to ask the question!   

From the sound of it, you may not have to mess with the springs, just lube what's behind the plate, starboard side above the dipstick.

[Braxton]

So I tackled the repair yesterday.   I had aborted a previous attempt the day before for the lack of proper tools on board.   Once I had the proper equipment everything was pretty straight forward.   Here is a rough summation of what I did.

1) Turned off the fuel flow using the valve at the tank.    (It turned out that this wasn't truly necessary as I never exposed the fuel pathway directly.  Still its a good idea to shut off the fuel just in case something goes sideways).

2) Replaced the gasket on my raw water pump.   The pump was leaking enough that it had coated almost everything with a mist of salt water.   Ken gets a prize for correctly identifying a water leak as the root cause.

3) Removed the throttle assembly.   This comes off easily.   The bolts on my engine took a 15/32 socket.   You only need remove the two bolts that hold the assembly to the block.  After those are of the cable and lever arm will drop out of the way so that you can...

4) Remove the barrel nut off the end of the shut off cable.  This combined with step 3 will expose the fuel shut off switch.

5) Remove the four bolts that hold on the fuel shut off switch.   To do this I used a 10mm socket which fit exactly.  I suspect that the correct size is a 13/32 but I didn't have a socket of that size.   The 10mm fit well so I didn't sweat it.

6) remove the fuel shut off switch.   It was stubborn for me until I found a trick.   There is a small ledge just forward of the switch.   A screw driver levered on this ledge lifted the switch out very easily.   So easily I almost believe that that is what the ledge is for.

7) My original idea was to further disassemble the mechanism and thoroughly clean and grease it.   There is a socket for an allen wrench that runs through the lever and I believe would have facilitated this.   However, I failed to have the correct size allen wrench so I was not able to do this.  Instead I lubricated the joint between the outside lever and the switch housing while working the switch back and forth.   After a few minutes of this (with repeated lubrications) the switch sprang back under its own power.   It is important to note that the switch must return on its own.   Just getting it to the point hat it moves easily is not enough.   It must be free enough for the spring to do all the work.

8) Reassembled.  The only trick here is that the internal lever arm must fit precisely into the mechanism inside the engine.  In the pictures look for the small metal block in the red circle.   The lever should be directly behind that.   If the switch is returning to its resting position fully then it should be lined up already.   If it doesn't fit in then you should go back to step 7.   During reassembly I replaced the gasket for the switch.  Universal, part number : 299516

9) Put the throttle back on, open the fuel and fire the engine up.   Smile in glee as it stops and starts as designed.

Now that I've been through this I plan on dropping a drop of penetrating oil lubricate onto the switch about once a month.   I expect that this will keep it operating smoothly.


Pictures:

1) A detail of the external joint between the external lever and the face of the switch.   Notice the crystallized salt.   This was strong enough evidence to convict the leaking water pump as the cause.   This joint here is where I applied the lubrication.

[Braxton]

2) The switch before removing the throttle assembly and shutoff cable.   Notice how three of the four bolts are obstructed.

[Braxton]

3) The switch after the throttle assembly has been unbolted and moved:

[Braxton]

4) A detail of the internal workings of the switch.   (Sorry about the focus) This part of the assembly appeared to be internally lubricated.   I made sure that I did not get any WD-40 on this side of the switch.

[Braxton]

5) The internal part of the switch.   The lever arm in the previous picture fits directly forward of the small metal block circled.

[Ron Hill]

Braxton : I'm sure that you feel great just having solved a problem - good show !!! 
What do you think was the cause of that lever freezing up??