Perkins 4108 starter bad?

[Scubaseas]

Originally Posted by Cadence

Try rapping the starter with something like a large wrench.
The brushes could be the problem. If so it may work but a new set of brushes are probably in order.

Sorry if the starter is a permanent magnet type you can easily break the field magnets by doing this. If you must beat on it do not beat on the motor case but on the nose cone. "Tap" on it.

[Cadence]

Originally Posted by Scubaseas

Sorry if the starter is a permanent magnet type you can easily break the field magnets by doing this. If you must beat on it do not beat on the motor case but on the nose cone. "Tap" on it.

I didn't think rapping meant beating the $hit out of it. Just enough to get worn brushes to seat on an armature that could probably stand to be burnished.

[doog]

several replies are very close. Its not likely to be hydrolock and you shouldnt need to close the intake on shutdowns. I had JUST this exact symptom with the same engine, and I discovered the internal soldiering on the battery cable was not well flowed, and the battery end heated up and melted out the lead around the wires causing a low or dead battery symptom which I once replaced the battery to correct before I finally found it. I could share photos of the terminal which finally flowed out the side with a liquid pool under heat stress, and when I replaced this battery lead suddenly all was well..Its a high cranking amp draw but well within the starting battery if fully charged and can look like a bad starter or solenoid but just a hidden resistance in the lines will trigger just this symptom. Hard to detect it with a meter but you'll feel warmth on the terminal if you touch it during cranking..possibly VERY hot..I had my starter and solenoid apart and going through everything when I could see nothing was wrong, and finally noticed the telltale pool of lead melted out of the battery end of the starter lead..and boom! I connected the dots. Ive also had warm terminals on the house batteries and re soldiered the terminals and the heating went away when properly flowed with a good, solid conductivity established.

[Boatyarddog]

Originally Posted by tradrockrat

Hi all -

So the inevitable fun has begun. The "Excellent running condition" Perkins that came with our boat has already had 3k worth of work done to it, and the truth is I have zero experience with diesels, so all specific knowledge of this engine is completely absent from my skill set. I'm totally comfortable learning by doing, but issues like today require a base level of experience I don't have.

My engine ran two weeks ago. Today the engine would not turn over. Behaved like a classic example of a dead battery - clicking sound, the whole thing. The only problem? The batteries were completely charged, and even adding the house bank resulted in nothing - engine would not turn over at all.

Put the multimeter on the battery and saw no drop in voltage when trying to engage the starter motor. Put the multimeter on the starter motor and saw a reading drop to 2.3 volts when my wife turned the ignition switch.

Before I buy a buy new starter motor, is there anything else that can cause this on a Perkins 4108?

I mean, this motor gauge cluster has a stupid black button (two stupid black buttons actually) that do God knows what, and when I gave up trying to start the motor and began the "I'm a stupid guy who's just pressing buttons now" phase of mechanical desperation, pushing that black button resulted n my voltage meter on the instrument cluster dropping form 12 V reading to a 10V reading. I'm assuming that this is just crap wiring issues from a 42 year old boat and is probably some kill switch (and the other one is probably a pre-heat?), but I'm going to feel real stupid if I buy a new starter motor and there's just some fuse I don't see that blew.

Additional information - I recently took the alternator output off of the starter motor and ran it to the housebank for charging reasons. I rechecked all wires and connections at the starter and all is tight and clean, and the engine DID start after I did all that and ran for 30 minutes before I shut it off - that was 2 weeks ago and the last time it ran.

Any advice? Thanks

Use some jumper cables, jump from the charged battery to the + red starter cable, and negative lead to the - cable and engine block.
Touch the starter solenoid small lead to the + of the starter you have jumped (red) cable with wire or screwdriver.
Should crank if the starter is good.
I believe you have 1 or more bad connections, or cables.
Be sure to clean the connections at the battery first then test again.
I had the very same in my 108 turned out to be a corroded - cable.
Couldn't tell from looking at it because the corrosion was hidden under the cables insulation.

[Scubaseas]

Originally Posted by Cadence

I didn't think rapping meant beating the $hit out of it. Just enough to get worn brushes to seat on an armature that could probably stand to be burnished.

Indeed. Didn't think you did but I have no idea how many Joules are in a rap. "Large wrench" to me seems like a small hammer. "Rapping" to me implies more than one strike and with some authority. Even a "tap" with a large wrench can crack a starter magnet.



Seen a lot of starters with broken magnets and scratches on the case in my 55+ years of pushing a wrench for a living. When starters had field coils you could tap, beat, persuade, cajole, pound, thump, bump or rap them without any issue. Most starters these days are permanent magnet types however. Brushes do get stuck and tapping the starter may indeed free them up. Just be careful doing it and don't rap the case where the magnets are. If you must rap do so on the nose cone or the brush holder plate. No offense intended but not everyone here may have the knowledge you do.

[tradrockrat]

Excellent advice everyone. Thanks again. As I said earlier, I'm headed down tonight and I'll make this my Tuesday project.

First thing I'm going to do is buy a solenoid to have a spare because that's just smart anyway (maybe a whole new starter and make this one a spare?)

Second thing I'm going to do is jump the solenoid with a screwdriver to see what happens. This is also where I'll GENTLY tap the starter with a wood handle (swinging metal wrenches near a starter seems....risky...to me)

Third I'm going to spend money I might not need to spend to replace the negative cables and maybe terminal blocks as well with new ones from the engine block all the way to the battery - those cables could be anywhere from 1-42 years old - piece of mind by replacing them is worth the cost to me.

If it isn't fixed, I'll check for hydrolock, re-read the Perkins manual, and then break out Caulder and get to work.

[Cadence]

Originally Posted by Scubaseas

Indeed. Didn't think you did but I have no idea how many Joules are in a rap. "Large wrench" to me seems like a small hammer. "Rapping" to me implies more than one strike and with some authority. Even a "tap" with a large wrench can crack a starter magnet.



Seen a lot of starters with broken magnets and scratches on the case in my 55+ years of pushing a wrench for a living. When starters had field coils you could tap, beat, persuade, cajole, pound, thump, bump or rap them without any issue. Most starters these days are permanent magnet types however. Brushes do get stuck and tapping the starter may indeed free them up. Just be careful doing it and don't rap the case where the magnets are. If you must rap do so on the nose cone or the brush holder plate. No offense intended but not everyone here may have the knowledge you do.

I should have qualified it in ergs.

[FionaJC]

I have the exact symptons. I removed the starter motor and found it was OK. I cannot turn the crank. I have removed the injectors and still cannot turn anything. I am in the process of removing the head. The water was turned off but I think the seized cylinder is the one that had the exhaust valve open for quite a while. Ill be interested in your results and Ill tell you mine. Mine is a 4107. I poured in Diesel to each pot, then Diesel/white spirit and lastly tried Marvel Mystery Oil. I have one cyclinder that wont drain, one takes a few days, one a few hours and another 15 minutes. Hope this helps.

[geoleo]

Originally Posted by Cadence

Try rapping the starter with something like a large wrench.
The brushes could be the problem. If so it may work but a new set of brushes are probably in order.

Great Advice ; the brushed hang up in their raceways and can stik.

[Cadence]

Originally Posted by geoleo

Great Advice ; the brushed hang up in their raceways and can stik.

I'm glad someone else has experienced this problem. In my experience when they get short from usage and the braided lead keeps them from sliding down.

[1affiah]

You've gotten a lot of good advice so far, the vast majority of electrical problems are related to dirty/corroded connections, bad grounds, wiring, terminals, etc.

Before you invest in a new or rebuilt starter, even if you decide yours is OK for now, take yours to an automotive electrical rebuilder for an overhaul. Same is true for most alternators, they can increase the output and convert to a "smart"
regulator if you don't already have one.

Also, most 4108 parts (except for heat exchangers) are available from farm supply stores, there are lots of these out there on farm machinery.

Great Motor, Enjoy!

[Bycrick]

The picture of the frayed cable shoes why the crimp-then-solder crowd are wrong. It’s hard to tell whether the corrosion around the lip of the lug is solder or not. But once you get moisture in the wire, the solder isn’t going to help because the corrosion will be inches away from the lug, under the insulation. You won’t see it even if you remove the heat shrink to inspect. Sometimes you can feel it by moving the wire back and forth. I’ve seen a battery cable like the one shown burn through and catch fire when they tried to start the motor.

[sailor_ed]

I cannot comment on the starter and you've gotten good advice on that anyhow. However:


"I mean, this motor gauge cluster has a stupid black button (two stupid black buttons actually) that do God knows what, and when I gave up trying to start the motor and began the "I'm a stupid guy who's just pressing buttons now" phase of mechanical desperation, pushing that black button resulted n my voltage meter on the instrument cluster dropping form 12 V reading to a 10V reading. I'm assuming that this is just crap wiring issues from a 42 year old boat and is probably some kill switch (and the other one is probably a pre-heat?), but I'm going to feel real stupid if I buy a new starter motor and there's just some fuse I don't see that blew."


The button that causes the voltage drop may be the cold start device. The 4-107 /4-108 doesn't have individual cylinder heaters but instead has an intake heater. To tell if this is true remove the intake cover and have an assistant push the button. In a few seconds you should see a coil inside the intake glow red. If not then my guess is wrong! The manual may tell you more about this device if it is there.


You should not need the cold start unless the engine block is below about 40F or your compression is low. Oftentimes it is not even hooked up. It needs both fuel and power to function.



Sorry if this is slightly off topic but maybe it will help you understand your engine. Good luck!

[nortonscove]

Recently had the same issue. Took it off and cleaned up the connections. Also looked inside to see that all was well. Put it back and worked as usual. Not a complicated piece of kit so don't hesitate in having a go yourself as new skills will never go astray.

[waterman46]

Originally Posted by Uncle Bob

Just a quick question, you did close the water intake when you last shut down the engine didn't you?

That post could really confuse a newbie. There is no reason related to engine maintenance, to close the water intake each time you shut down the engine. Only need to close it if you are doing a lot of cranking by starter motor before engine starts.


You may optionally close the intake when leaving the boat, but that's to prevent a sinking if there should be a leak between the thru-hull and the engine.


To the OP, it sounds like you may indeed have a bad starter motor, but there is not sufficient information here to diagnose. If you can remove starter motor easily then could have it checked at minimal cost. Next would be to get a tech to look at the problem since it sounds like you are not familiar with the entire circuit.