Fuel solenoid hold down circuit

[Jeff Green]

It has been determined that my intermittent start problem on my port engine is due to  low voltage to my red wire (hold down circuit).  The mechanic explored as best he could at the time, but said he would have to consult an engine wiring diagram before going any further.  After having been in for annual service, everything was determined to be OK, since it didn’t act up for them at that time.  Luckily yesterday it exhibited the no start issue in their presence.  Has anyone had this issue and if so, what was your solution.

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[Jeff Green]

So far, so good!

So far we have not have any starting issues.  Our 20 day trip up north was perfect.  I will feel more comfortable with the fix after a full season in case it is related to the colder months and recurs over the winter.

[Ken Bryant]

Good to know – I have one of those onboard and never even thought of that as potentially part of the problem.

[Joe Witt]

I had that problem two years ago. Intermittent won’t stay running. Finally found out the culprit was the Fireboy  system electronics under the helm. 

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Ken Bryant

[Joe Witt]

I had that problem two years ago. Intermittent won’t stay running. Finally found out the culprit was the Fireboy  system electronics under the helm. 

[Jeff Green]

Today my tech replaced the fuel solenoid and also suggested that I replace the kill switch at the upper helm on that side.  He replaces a lot of them and it may be the cause of the intermittent low voltage.  Now only time will tell.  

[Ken Bryant]

Solenoid Ground

I was chasing a similar thing on one of my engines – random shutdown at cruise is a bit unsettling.

After a lot of google-fu (which found a lot of sbmar.com hits) I took the ground off the solenoid plug and grounded it to the block.  Haven’t been out for an extended run since but I was able to run at the dock without a shut-down for an extended period, which it wouldn’t do just before I redid the ground.

[Jeff Green]

Today I removed the engine circuit breaker and cleaned all parts and connections as well as possible.  It would have been nice to have had a couple more inches of wire length to give better access.  It was as difficult as any dental procedure I performed  back when I was working. Yes, the mechanic was the one who found the intermittent low voltage.  I think I would rather spend the $55 for a new breaker rather than trying to connect the two wires and risk creating another issue. From my reading the simple wiring diagram I found on this site, it appears this breaker is between the key switch and the starter solenoid and the red wire to the fuel solenoid seems un-interrupted by any fuses.  It has always cranked very strongly, it’s that it dies after it runs for maybe two seconds.  It has never died after a successful start, so overheating and tripping has not been an issue.  Of course it started and ran fine today before my disassembly, so only time will tell if I have solved the issue or whether the saga will continue.   

Thanks for your thoughts and any future suggestions.

[Clark Leighs]

It is not unreasonable to bypass the C.B. as a test.    NOt to be done for long term though.    It is there as protection of the controls and you should keep it.   However, I would also check the wiring connected to it.   The terminals MUST be clean of oxidation, the crimps tight and the actual connection points  tight.       If there is a problem with the connections that can cause a heat up of the C.B. itself which can cause a trip even though there is nothing wrong with the actual C.B. Do not just look at the connections. Disassemble them lightly, BRASS wire brush the contacts, use a silicone dielectric grease and LIGHTLY smear the contact area  to exclude oxidation or at least seriously slow it as you reassemble.      Test again.   If there is further trouble then the next best thing is some amp draw testing to see if the breaker actually is seeing more current than it is supposed to do.   Borrow a clamp on ammeter,  or  borrow someone with one.    If the meter shows current less than the C.B. rating then  consider  getting and installing a new C.B.    

 

I suspect you have checked the actual voltage at the fuel control solenoid, correct?  Seen it low?

 

 

[Jeff Green]

It has been suggested to me to check the connections on the engine circuit breaker with the red button on it.  If the connections are not the problem, then try bypassing the breaker by connecting the two red wires directly to each other check if the issue is the breaker itself.  I’m not sure what the risk is to connecting these wires directly for the short term.  I’ve heard that it is not unusual to have to have to replace these breakers.  The engine always cranks fine, but shortly after catching and running for about two seconds, the fuel solenoid releases and the engine dies due to a low voltage being supplied to it.

[John]

BRB

[Author]

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