Perkins 4-108 Starting Problem

[cloudman42]

May I ask the forum for any insight to my problem with my perkins 4-108. When I first bought the boat I would go to start the engine and the voltmeter at the starter panel would read 12 volts but as soon as I cranked it the solenoid would click and the voltmeter would drop to around 10 volts and the engine would not crank. Curiously I could try this several times and maybe on the 4th or 5th try I would change the battery switch to both but it would still happen but maybe on the 2nd or third try the engine would crank. Weird I know.

So I initially thought that the starter was bad. I replaced the starter with a brand new one and still had the same symptom. I posted a question to the forum and you suggested that the starter battery could be not charged because of the battery combiner was not passing through a charge as the main battery charging voltage was too low. I changed the static voltage control on the battery charger/inverter to up the voltage to 13.4 and the battery combiner then successfully passed a charging voltage over to the stater battery.

I haven't been sailing for a while but this weekend it happened again. does anyone have any idea what could cause this. I am thinking it might be the wiring from the starter switch???

[btrayfors]

Originally Posted by cloudman42

May I ask the forum for any insight to my problem with my perkins 4-108. When I first bought the boat I would go to start the engine and the voltmeter at the starter panel would read 12 volts but as soon as I cranked it the solenoid would click and the voltmeter would drop to around 10 volts and the engine would not crank. Curiously I could try this several times and maybe on the 4th or 5th try I would change the battery switch to both but it would still happen but maybe on the 2nd or third try the engine would crank. Weird I know.

So I initially thought that the starter was bad. I replaced the starter with a brand new one and still had the same symptom. I posted a question to the forum and you suggested that the starter battery could be not charged because of the battery combiner was not passing through a charge as the main battery charging voltage was too low. I changed the static voltage control on the battery charger/inverter to up the voltage to 13.4 and the battery combiner then successfully passed a charging voltage over to the stater battery.

I haven't been sailing for a while but this weekend it happened again. does anyone have any idea what could cause this. I am thinking it might be the wiring from the starter switch???

Could be several things at work.

1. bad ground (connections or wiring)
2. loose or bad connections in the positive circuit, including battery switch
3. bad batteries (greatly reduced capacity)
4. inadequate charging voltage
5. battery switch defective (i.e., contacts corroded)
6. bad solenoid

It could be any combination of these factors. In any event, what you describe smacks of inadequate voltage reaching the starter.

Hint: get some decent meters and learn how to use them to trace voltage drop, current output, etc.

DO NOT assume that it's just one or two problems. From what you describe I'd suspect at least two and probably more problems.

Your charging voltage is WAY too low. Flooded batteries should be charged at 14.6-14.8VDC in the absorption phase, and floated at 13.2-13.6VDC. Probably the low charging voltages have resulted in significant loss of capacity in your batteries thru sulfation.

Bill

[leftbrainstuff]

Check for voltage drop while under load. Also load test the battery or check specific gravity before replacing any components.

Always start with checking the basics. Voltage, current and resistance.

Sometimes a starting solenoid can stick but you've swapped out the starter already.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[Cheechako]

1) Clean cable ends... especially those that bolt onto the engine frame.
2) Solenoid
3) Start button or switch possible also
4) out of the blue I had trouble with my 4-108 and it was the plastic wire connector on the back of the engine. Open it up and look at the little pins etc... clean them

[jkishel]

Batteries/charging could be bad, but since they are showing 12 volts the most likely cause of thius is a bad connection or connections between the batteries, the starter and the ground. Start with the ground connection. Find the black battery cable that is bolted to the engine block or cross member somewhere. Unbolt it, clean up the terminal and its mating service and rebolt it, good and tight. More often than not, this is the problem. However, while you're at it, do the same with each of the cable connections at the batteries and the connection at the starter. Make sure the connections are clean, good and tight (replace any wing nuts with stainless hex nuts). remove and neutralize any corrosion and corrosion product. Replace any cable terminals that are loose, corroded, broken, etc., or just replace the problem cables. Many older boats have battery cables that are really undersized based on contemporary standards. If this is the case, buy and install larger new custom cables (Greg's Marine Wire is a great source). Assuming these are lead acid batteries, top them up with distilled water. Consider fusing the battery banks if they aren't fused so you don't unintentionally burn the boat to the water line some day. With a new starter and sound adequately sized cables and connections the engine will start with a lot less than 12 volts at the battery.

[BentP]

Go through all connections and relays, it sounds like a bad connection somewhere.

[Cadence]

Not knowing how you are wired it does not sound that odd, reading your first paragraph. It would appear your start battery is not charged or is bad. The delay is the time needed for the other bank to get it up the voltage along with them, or average, when you go to both. What is your charger charging? Try leaving it on both, for awhile, when charging, over night at least, switch to the primary starting battery and try kicking over the engine.

[Boatyarddog]

Batteries that show only 12 volts are not charged.
That standing voltage should be 12.40 or more.
And shouldn't drop to 12 after cranking.



Sent from my iPad SV Cloud Duster

[Boatyarddog]

My 4-108 had new batteries and would only click.
Ha!
Turned out that the - cable had a corroded length from the battery under the insulation, of about a foot.
I replaced this section, no more problem.
Excessive resistance in the cable it self, you couldn't see it, only a slight swelling of the insulation.
I started to explore that suspect area and found that "resistor". Just a nick in the insulation can cause this to happen over time.
It's why we try not to run cables low in bilges.
Attachment 95458


Sent from my iPad SV Cloud Duster

[btrayfors]

Originally Posted by Boatyarddog

My 4-108 had new batteries and would only click.
Ha!
Turned out that the - cable had a corroded length from the battery under the insulation, of about a foot.
I replaced this section, no more problem.

Sent from my iPad SV Cloud Duster

Thanks for posting those pics. They make my skin crawl.

I hope you replaced more than "this section".

Several problems visible, viz...

1. That's not marine cable;

2. The crimp is terrible; looks like it was done with one of those hammer-crimpers; and

3. No adhesive heat shrink installed over the lug and cable end.

This sort of crummy wiring is looking for trouble, installed low in the bilge or not.

Here's what a good crimp looks like, before applying the adhesive heat shrink tubing. And here's a decent crimp tool.

Attachment 95458Attachment 95459


Bill

[CptLawrence]

if a jumper wire turns the engine over easily then that rules out a bad or weak battery and points to a bad switch or wiring. be careful not to connect the jumper to the wrong place. if wet weather seems to be a factor then clean all the connections you can get to. if the switch is exposed to weather and not covered by plexiglass or in a damp compartment it could be your problem

[Cheechako]

Don't rule out the multi pin connector on the engine either (as I mentioned earlier) had that trouble on my 4-108. The connector was in a rubber cover etc but still ended up being the culprit when I started having occasional "not turning over" issues.

[Boatyarddog]

Yes, it's bad section was replaced with a proper sized butt crimp connector and heat shrink, crimped with a proper lug crimper.
The section was near the battery and not in the bilge.
All good now.funny you couldn't see the bad section because of the insulation, but I just cut a little back and that's what I found.
Gifts from the previous owner.
It is marine grade, installed in 1979, before they marked it MarineGrade on the jacket.



Sent from my iPad SV Cloud Duster

[Doctor]

Hi There
This is off your topic, but I see you have an Offshore 40. I am looking at one right now and would be interested in your opinions on the boat. Any weak points, and strong points would be helpful. This one does not have mast furling and is a lehman diesel, so apart from the engine.
Thanks, Bryan