Sticky Shut Down Solenoid and Governor connection

[Genevatexan]

Hello Hatterases,

Sea Lion here with a '76 Bertram 42 DCMY with 4V Turbo Detroit Diesel 6-71s. I follow you Hatterases because you have an excellent forum and knowledgable owners. I have owned this boat 2 years and bought from a 20 year owner who was a knowledgable diesel guy.

Here in Texas the summer heat is near it's peak right now and my port engine does not want to shut down with the electric solenoid switch. I pulled down the solenoid, ordered a rebuilt unit, bolted it up, and it works perfectly cold, but the shut down also sticks when the engine is hot.

The alignment of the rod connecting the SWVS governor to the solenoid could be a degree or so out of alignment with the rod exiting the solenoid piston, but does not appear enough so to create a bind.

Therefore, my assumption is some heat related resistance in the stop lever, which is part of the governor. I do not understand these governors, and wondered if someone could suggest where such heat related resistance could be and how to overcome... could it be a lubrication issue, a wear issue or an adjustment issue?

Our only choices right now are to move furniture, pull carpet, pull up inspection port and give the lever a tug while someone operates the solenoid switch, or use the manual T-lever to close the air intake flap. I dont like using the T lever because because it is said to possibly lead to blower seal failure and exhaust valve stress.

Since we know the solenoid is good, and a manual boost of the connection rod to the stop lever on the governor is enough to kill the engine, I think its reasonable to guess the bind is on the stop lever side.

All help appreciated,
Sea Lion

 

[bobk]

My port solenoid does the same thing once in a while. My solution (after I bought a new solenoid) is to clean and re-tighten the electrical connections and spray the connecting rod at the solenoid end with WD40. Seems to last a year.

Bob Kassal
Chateau de Mer
1981 48MY

 

[REBrueckner]

I would disconnect the solenoid arm and feel for resistance....Is the old solenoid arm working smoothly????

WD40 is a lousy long term lubricant........wipe the arm with a small piece of soaked paper towel using engine or a finger dipped in oil...that will adhere a lot longer....

 

[Genesis]

It's not the governor. At least it better not be. If you have things binding up in there you have a potential disaster on your hands; anything that prevents the governor from putting the fuel racks where it wants to is a potential runaway situation, especially when out of gear.

Next time it happens (yeah, I know this is going to be a major PITA) see if you can disconnect the solenoid it and move the lever manually to "STOP" with your hands and detect the binding - and if so, where it is. There should be no binding. If there isn't in the movement of the lever itself it's in the alignment of the linkage and solenoid. It doesn't have to be off much to bind, especially when hot.

Also check the hole that the return spring is in and that the pull of that spring is straight. I've seen misalignment of that spring's pull do this too, and it wasn't obvious why it was happening.

 

[rsmith]

It's not the governor. At least it better not be. If you have things binding up in there you have a potential disaster on your hands; anything that prevents the governor from putting the fuel racks where it wants to is a potential runaway situation, especially when out of gear.

Next time it happens (yeah, I know this is going to be a major PITA) see if you can disconnect the solenoid it and move the lever manually to "STOP" with your hands and detect the binding - and if so, where it is. There should be no binding. If there isn't in the movement of the lever itself it's in the alignment of the linkage and solenoid. It doesn't have to be off much to bind, especially when hot.

Also check the hole that the return spring is in and that the pull of that spring is straight. I've seen misalignment of that spring's pull do this too, and it wasn't obvious why it was happening.

Roger that, I had the same deal took the solenoid loose and realigned everything works fine. I use dow dc4 dielectric grease on everything. Wd 40 is too light duty and dosent last.

 

[Bill Allen]

On mine my port engine sometimes acts up shutting down. Found out if the throttle is not totally down (sometimes need to hold it down) it doesn't want to shut off. As soon as I pull back the lever to the stop she shuts down perfectly. Bill

 

[Genevatexan]

Excellent remarks, guys.

I will recheck the location of the return spring, carefully align the linkage rod to the stop lever and solenoid piston , and then watch the positioning of my throttle lever at shutdown.

As soon as I work through that I will report back. Just as additional input, I did feel the stop lever with the linkage disconnected and the resistance is quite light. I did not try this while running through, only with engines off, so did not know if the resistance increases with engine running. In addition, it is only an issue when hot, not when cold or warm.

btw- I have an extra shut-down solenoid, having bought two from a rebuilder in New Jersey at $150 each. I painted and installed one, but the second is now excess if there are any takers out there. Disconnected from the stop lever its strong and fast to react, so I beleive they are fine. They look brand new, can't see any rebuild evidence at all...better than the $300 I was seeing in some shops...

many thanks to all,
Sea Lion (Kent)

 

[Genevatexan]

And, if I figured it out, a photo of the Sea Lion as well....

 

[Genesis]

Note that there are multiple holes on the shutdown lever - check the travel too. The lever has to go all the way to the stop or it won't reliably shut down and it MUST NOT be pulled at all (that is, it must be hard on the "run" stop) when not energized. If not there's a risk of the governor doing bad things - that is, there are only two valid positions for that lever - "STOP" and "RUN", both fully against their respective stops.

If you're too far "in" on the lever (too far in on the hole selected for the rod) the solenoid won't develop enough pull, too far out and the lever doesn't go all the way to the stop.

 

[Genevatexan]

Here's my situation now:

1. The solenoid piston rod was substantially misaligned with the stop lever connecting rod due to a change in re-assembly. One washer made the difference on the governor lever side to realign and reduced friction on the solenoid arm as it moves in and out. A retest on a 102 dgree day resulted in a clean shut down but doesn't guaranty the problem is solved quite yet.

2. As you noted, the governor lever was free and smooth and no problem was found there after disconnecting. I did improve the pull-alignment of the return spring slightly.

3. An uncle in the automobile repair business suggested heat related resistance and resulting voltage drop as a possible culprit as well. I started testing at the On/Off/M-on switch on the dash and recorded inbound voltage at 13.2 V. I then checked outbound voltage in the "On" position- 13.2. Then I checked voltage in the Momentary-On (M-On) position when the stop solenoid is energized- 12.2. I lose a full Volt at the switch. Is this normal for an M-On switch? (seems unlikely). From there I recorded cold operation voltage at the solenoid at 11.9 to 12.0, so another .2 volt slipping away in the wiring.

New questions:
A) Should I be losing 1 volt in a "momentary-on" switch from source to output?
B) Are electrical devices such as the stop solenoid expecting to see source voltage (13 plus) or are they configured to expect wiring related voltage drop? 11.9 at the solenoid sounds too low....

I know I have one clean test, but don't like the apparent voltage issue and would like to clean that up as well, just in-case the new solenoid and improved alignment are just part of a constellation of causes....

Many thanks, making progress!