Perkins 4108 starter bad?

[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

[Uncle Bob]

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

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

[pdxsailordiver]

Could be bad contact in solenoid.

[tradrockrat]

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?

AHHHH...I could have hydrolock! A term I've only heard and never discussed...Thanks! Now to research how to see if I do have that and how to fix it...

[tradrockrat]

Originally Posted by pdxsailordiver

Could be bad contact in solenoid.

Is there a simple way to test that? Thanks

[Uncle Bob]

Originally Posted by tradrockrat

AHHHH...I could have hydrolock! A term I've only heard and never discussed...Thanks! Now to research how to see if I do have that and how to fix it...

A simple test is to try turning over the engine with a socket and breaker bar using the crankshaft nut on the front of the engine. If you can turn it over relatively easily then no hydrolock, most probably starter problem.

[tradrockrat]

Originally Posted by Uncle Bob

A simple test is to try turning over the engine with a socket and breaker bar using the crankshaft nut on the front of the engine. If you can turn it over relatively easily then no hydrolock, most probably starter problem.

Great. I had to come back home from the boat today, so I'll head back Tomorrow night after work and spend a day or two on the boat working out the issue. Appreciate the help.

[Reefmagnet]

@ 2.3 volts I'll just about bet it's a bad connection in the starter circuit. Don't forget the circuit also includes the negative earth lead connected to the block of the engine. Easiest way to check with a meter is to place the probes across each suspect connection (including the solenoid terminals) looking for the "missing" voltage reading with the starter engaged (or hottest joint!). The higher the voltage reading, the higher the resistance through the connection.

[Toaster]

Try "shorting" across the two solenoid terminals with a big screw driver (watch for sparks) and see if the starter turns. A clicking solenoid is not necessarily working - there might be a bad contact. I've had two fail in the 10+ years I've been using our 4-108. If this is the problem, it's not hard to start the engine in this way. And carry a spare solenoid.

Good luck!

[tradrockrat]

Thanks all! I have to say it's great being able to pour out a problem and get instant advice here. I'll play around with all of this tomorrow morning when I get back on the boat.

[rbk]

Also check for bad/old cables in the starting circuit. A lot of heavy gauge cables are open crimped allowing for corrosion and can cause very high resistance especially when they are hidden at the back of the engine and never see the light of day.

[freakytiki]

And of course..a new to rebuilt starter is around $125. Not hard to put on. I have a perkins 4108 in my !973 Cal35. She smokes (just started when i add a new fuel tank)but that 5oHP keeps on running

[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.

[Exctyengr]

In addition to all of the above, (especially the hydrolock), check the ground

[jkishel]

First, check the battery cable connections, especially the negative (black)cable connection to the engine block. Trace the black cable back to the batteries and check any connections along the way (bus bar, etc.). Be sure all cable connections at the batteries are clean and tight. This is the most likely cause of excessive voltage drop.