Stopping solenoid not working

Hello all.* Just got back from delivering my new to me Monk 36.* I met with the PO for about an hour to go over any last minute items and idiosynchocies.* He showed me all log books, spare parts, canvas covers etc.* So as we're getting ready to shove off he had one more remark: "if you run the port engine for more than about two hours the stopping solenoid might not work.* you might have to go down into the engine room and push on it to get the engine to stop."

Good thing he said that because we had over 5 hours to run in order to get back to my home marina.* We stopped about mid way to top off our tanks and sure enough I had to locate and push on the solenoid to stop the port engine.* When we got home, I had to do both engines that way and the next day after about an hour I still*had to manually shut down both.

Questions:* are these just old/bad solenoids that need to be replaced?* Why do they work fine if the engines run for only a few minutes but do not after a longer period of time?* If they do need replacing, how hard is the job?*

Thanks in advance.

Woody, start with connections for the wiring first before you replace the solenoids and find out the new ones don't work either. An easy check, just jump a pair of wires to the units from your battery. If they work, look elsewhere, if not, replace them. Chuck

The solenoids activate, they just don't push out enough.* My assumption is that once they get good and hot they don't work as well as they do when they're cold.** I'll try to locate the correct parts and replace them.

"The solenoids activate, they just don't push out enough"

See if there are slots in the mount.

If not a drill can make the mount hole longer so you might simply adjust it.

Before you go drilling new mounting holes or otherwise modifying the system look at it this way - it obviously worked when new and when cold but when hot the solenoids are being powered on demand but they don't move enough now.
1st thing, when energized are they getting a full 12 volts or is there a wiring fault somewhere, probably near the engine, that is becoming high resistance when hot and thereby not allowing enough power to reach the solenoids?
Have the 1st mate energize the solenoids and measure , right at the solenoid if possible, the applied voltage. My guess is that there is not full voltage on either of them when they are hot - and don't use the engine block etc for the negative measuring point because that may be where the problem lies, voltage drop from the solenoid negative / mount back to the battery!
Just one guys thoughts but more time than enough I have found this sort of fault in troubleshooting power problems.

John Tones MV Penta
Sidney, BC

My guess is the voltage is fine , either they pull or don't.

Since they worked when new the usual wear and looseness from 20-30 years of vibration has taken its normal toll.

Let us know what cured the hassle.

I think Chuck and Penta have the right approach. But I have to agree with FF, either they pull or don't. It might have to do with metal expansion when they are hot. Anyway, it's a weird problem. I had a similar issue with mine but it ended up just being a bad connection.

-- Edited by Fotoman on Wednesday 30th of June 2010 07:14:33 AM

this thing happenned on my ford lehman and i fix it easely.
the selenoid was not operating all the way....so i took it apart and kleen everything(plunger and inside ) with brake cleaner.It never fail since that time.

septembre wrote:

this thing happenned on my ford lehman and i fix it easely.
the selenoid was not operating all the way....so i took it apart and kleen everything(plunger and inside ) with brake cleaner.It never fail since that time.

Click to expand...

I had the same problem with the starting (preheat I guess) solenoid on a genset.* This was a charter boat, and they told me to just push on it when starting and that worked fine.* So what we're saying here is that either 1) the solenoid isn't getting full voltage or 2) the solenoid is dirty and needs cleaning and nothing else.

I know the solenoid activates, since I was able to find it in the first place by having the mate press the stop button and I watched and listened for a click and movement, plus I knew it would be near the injection pump.* If you fire up the motor it works fine after a few minutes and only seems to fail after some time with the engines running.

I guess I will first check the voltage and if that seems good I will take everything apart and clean.* If that doesn't work I will obtain new solenoids and replace altogether.* If I'm not mistaken, a solenoid is just an electro-magnet and shouln't ever wear out, but they are > 25 years old.* The fact that I can push it manually means that it isn't pushing out all the way so that is the root cause and I will concentrate on that.** Sound reasonable?

thanks everyone for your help.

Woody

*

I can't remember what engines you have. If they are Ford Lehmans (120 or 135) a call to American Diesel to Bob or Brian Smith will probably get you the answer to your dilemma. They know more about Lehmans than anyone else on the planet, plus they stock parts for them.

As a major believer in the KISS principle, I'm grateful that our old 1973 boat with FL120s has mechanical shutoffs instead of solenoids. Pull the knob up on the instrument console and the Teleflex cable attached to it pulls the shutoff lever on the engine down below. No solenoids to crap out, no wires to trace, no connections to corrode.

Quick update:* I did some testing and the voltage on the entire Port side is just over 12 volts (the side with the flaky soleniod).* Starboard measures 14.* This is according to the voltage guage on the console.* I didn't get a chance to measuee with a multi-tester.* Turns out if you just hold the stop button in for maybe 5 or 6 seconds it does eventually stop.* Does this mean my alternator is going bad?

-- Edited by Egregious on Thursday 29th of July 2010 02:02:23 PM

Or your guages are wrong or you have a bad or loose connection some where.

Likely means the solenoid is bad. *It is getting 12 volts and should work just fine. *You are going through a lot of heartache for a part that costs...50 bucks???...I don't remember. This happened on my last boat.....Perkins 4236. I replaced the part. End of problem...never to rear it's ugly head again. They do go bad after 20 years or so.....

-- Edited by Baker on Tuesday 3rd of August 2010 07:05:21 AM

This problem doesn't exactly qualify as "heartache" ...
For that just see the thread about the oil cooler and transmission.

Before springing for a new solenoid I would take the old one off and clean it with electical cleaner, trying to get enough inside the casing to clean the space between the coil and the slug.

Blow it dry and squirt some light lubricant in alongside the actuator shaft. See if that has reduced the friction any. Hook it up to power and see if it moves freely and snaps quickly. If it does, reinstall it and worry about it in another 10 years.

A sticky solenoid can be cured by the cleaning processes, previously mentioned. I had a similiar problem caused by a "high resistance"/ Poor ground connection. A combination of a "sticky" solenoid and poor ground would be compounded when hot!

Welcome LadyMJ!!!

IF you actually are going to purchase a solenoid look into the cable operated , manually or electrically actuated from Murphy.

AS you upgrade to mechanical instruments , you will be able to use the auto secure function of each readout.

To my mind a diesel which will run to fuel exhaustion sans electric , should be monitored and set to control sans electric.

But then I am a blue water sailor at heart,

If I'm not mistaken, a solenoid is just an electro-magnet and shouln't ever wear out, but they are > 25 years old.

Click to expand...

No, a solenoid is an electromagnet that operates a mechanical device (a plunger). There is the electrical component which is either OK or open or shorted (or partially shorted) and there is the mechanical component which can become dirty or worn out.

Others have suggested cleaning and lubricating the mechanical parts and I agree with them.

Also mentioned was that one was receiving a lower voltage than the other. This indicates a resistance somewhere in the circuit. I would check all electrical connections and switches for corrosion or resistance.

I just went through this on my 36CL Grand Banks Lehman 120. It was a bad connection on the solenoid. The tab for the switch had corroded. When I checked the connectors it broke off in my hand!

I bought a generic replacement solenoid for $30 and it was a 20 minute job to replace.