Dead Starter, 3JH4E

laika

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Earlier in the year I had 2 or 3 incidents where when starting the engine for the first time after not having been used for a week or two I'd turn the key and nothing would happen. I'd then go down to the engine and ask my sailing buddy to start the engine while I was listening to the solenoid and inevitably the engine would start without problems and then work perfectly for the rest of the weekend. In all cases it was cold.

Last weekend was warm and we'd used the engine the previous weekend without problem. Turned the key: nothing. Went to the engine and sure enough, click from the solenoid when the key was turned. Shorted the power to the starter with my big screwdriver: took a small chunk out of the screwdriver but no sign of life from the starter. Electrical connectors all look ok, although I'm not sure what would be stopping the starter: A little googling suggests that smaller yanmars don't have have neutral switches to go faulty (but I could be wrong about that).

Ideas on what to check next? It's not like this is degraded performance: it's a working/not working thing. I'm not a massive fan of the local yanmar outfit so I'd possibly prefer to remove the thing and get it checked elsewhere (though recognising that the problem may not be the starter itself). Is removal likely to be a fearsome task? I'm a mechanical dunce but loking at calder's diesel book it seems like the task might not be too hard: the objective is to remove the thing from the housing rather than work out how to get the big chunk of metal off he enggine, yes?
 
Last weekend was warm and we'd used the engine the previous weekend without problem. Turned the key: nothing. Went to the engine and sure enough, click from the solenoid when the key was turned. Shorted the power to the starter with my big screwdriver: took a small chunk out of the screwdriver but no sign of life from the starter. Electrical connectors all look ok, although I'm not sure what would be stopping the starter: A little googling suggests that smaller yanmars don't have have neutral switches to go faulty (but I could be wrong about that).

If you damaged the screwdriver by shorting the two big terminals on the solenoid then this suggests the starter is faulty. The current has flowed through it or something else and it should have turned but might not have engaged . Take it to a local auto electrician who should be able to sort it.

The correct way to start with a screwdriver is to short the small terminal to the battery terminal on the solenoid which powers up the solenoid and this clunks and starts the engine. If there is no action from the starter following the clunk then either the contacts in the solenoid are faulty or the motor itself.

Many engines need the solenoid to be energised as this action kicks the pinion into the engaged position . However engines without a pre engaged pinion can be started by shorting the big terminals together.
 
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Not good enough for connections to look OK . They must be OK. Clean and remake negatives as well.

Shorting the main solenoid terminals together should spin the starter motor but unless the solenoid coil is also energise it wont engage with the engine.

Odd that you get a high enough current to damage the screwdriver without any action.............. Maybe its jammed ....... common thing to happen on inertia starters nut not on pre-engage types although I have one that does sometimes ......... Try turning the engine a bit by hand, If jammed it will free with a distinct click.

Dont understand what you mean by "the objective is to remove the thing from the housing rather than work out how to get the big chunk of metal off he enggine,"
 
I think by big chunk of metal he means the starter. Yes, you do remove the whole chunk, don't try to take it apart while it's on the engine. Then you just swap in the spare starter you of course carry aboard and see how that is doing, as you probably tried to start the engine because you meant to go somewhere ;-)

Look at the drawings to help and identify which bolts to undo, and look up the part so you have an idea which chunks come off and which stay. It's usually easy, apart from awkward access. Be careful with the cables, insulate them and don't let them dangle around and short out, the motor battery switch usually only disconnects one of them and if you have a VSR in front it may be surprisingly live anyways. Don't snap off any bolts, better to give it time and release penetrant than try and extract them later.

Your starter probably looks like this: NEW STARTER YANMAR MARINE ENGINE 3JH4E 3YM20 3YM30 4JH3E 1994-On 18219

The starter consists of two cylinders, a large one, which contains the motor and a smaller one housing the solenoid which drives forward the little gearwheel that engages with the flywheel on your engine.

Make sure the click you hear is really the starter solenoid (which makes more of a thunk than a click) and not just another relais in the vicinity, like a NC fuel solenoid or one that temporarily grounds the engine for starting.

Good luck, and with a OEM starter being only $70, it would be wise to carry one aboard for next time (or this time if it's broken).
 
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Make sure the click you hear is really the starter solenoid (which makes more of a thunk than a click) and not just another relais in the vicinity, like a NC fuel solenoid or one that temporarily grounds the engine for starting.

Good luck, and with a OEM starter being only $70, it would be wise to carry one aboard for next time (or this time if it's broken).

The Yanmar does has an additional relay in the solenoid circuit >>>>> called "starter relay " in the wiring diagrams in the owners manual.
 
Earlier in the year I had 2 or 3 incidents where when starting the engine for the first time after not having been used for a week or two I'd turn the key and nothing would happen. I'd then go down to the engine and ask my sailing buddy to start the engine while I was listening to the solenoid and inevitably the engine would start without problems and then work perfectly for the rest of the weekend. In all cases it was cold.

Last weekend was warm and we'd used the engine the previous weekend without problem. Turned the key: nothing. Went to the engine and sure enough, click from the solenoid when the key was turned. Shorted the power to the starter with my big screwdriver: took a small chunk out of the screwdriver but no sign of life from the starter. Electrical connectors all look ok, although I'm not sure what would be stopping the starter: A little googling suggests that smaller yanmars don't have have neutral switches to go faulty (but I could be wrong about that).

Ideas on what to check next? It's not like this is degraded performance: it's a working/not working thing. I'm not a massive fan of the local yanmar outfit so I'd possibly prefer to remove the thing and get it checked elsewhere (though recognising that the problem may not be the starter itself). Is removal likely to be a fearsome task? I'm a mechanical dunce but loking at calder's diesel book it seems like the task might not be too hard: the objective is to remove the thing from the housing rather than work out how to get the big chunk of metal off he enggine, yes?
If you shorted across the main solenoid terminals and power was seen to pass ( meaty spark and damage to screwdriver) then its more than likely the motor brushes are sticking. If your motor looks like that in no 4 ( pre engaged) and it didn't spin ( just the motor , not the engine) while you shorted the terminals then the above is very likely. A useful though not conclusive test is to give the motor case (towards the back end) a good 'rattle' with a hammer or some such which often encourages the brushes to slide forward in their holders and so make good contact. Then try the key and see if it works again. On the plus side the fact that the motor works occasionally is a good sign as the windings etc must be intact for it to work at all and what your looking for is a bad connection by and large.
 
Dont understand what you mean by "the objective is to remove the thing from the housing rather than work out how to get the big chunk of metal off he enggine,"

Calder's pictures of "removing the starter motor" seem to involve extracting the wire-wound motor from the casing. Until I attack it with a spanner I'm not sure whether I'm supposed to be extracting the motor from the casing or whether the casing itself can be removed from the engine. I had been thinking the former, but from the pictures of starter replacements like the one Yngmar linked to I'm leaning towards the latter

The Yanmar does has an additional relay in the solenoid circuit >>>>> called "starter relay " in the wiring diagrams in the owners manual.

I may be misunderstanding this but isn't it the case that the relay operates the solenoid which operates the starter, so if the relay was problematic the solenoid wouldn't be going thunk (and to clarify, it's a sort of solenoidy thunk rather than a quiet click)?
 
Calder's pictures of "removing the starter motor" seem to involve extracting the wire-wound motor from the casing. Until I attack it with a spanner I'm not sure whether I'm supposed to be extracting the motor from the casing or whether the casing itself can be removed from the engine. I had been thinking the former, but from the pictures of starter replacements like the one Yngmar linked to I'm leaning towards the latter

I'll have a look at Calder later but generally removal of a starter involves disconnecting the wiring, sometimes removal of a support bracket, removing two mounting bolts then lifting the starter motor complete with solenoid away from the engine.

I may be misunderstanding this but isn't it the case that the relay operates the solenoid which operates the starter, so if the relay was problematic the solenoid wouldn't be going thunk (and to clarify, it's a sort of solenoidy thunk rather than a quiet click)?
You understand correctly. My post was aimed at Yngmar.
 
Calder's pictures of "removing the starter motor" seem to involve extracting the wire-wound motor from the casing. Until I attack it with a spanner I'm not sure whether I'm supposed to be extracting the motor from the casing or whether the casing itself can be removed from the engine. I had been thinking the former, but from the pictures of starter replacements like the one Yngmar linked to I'm leaning towards the latter



I may be misunderstanding this but isn't it the case that the relay operates the solenoid which operates the starter, so if the relay was problematic the solenoid wouldn't be going thunk (and to clarify, it's a sort of solenoidy thunk rather than a quiet click)?
That is mostly true but I have read of cases in these pages where the solenoid was operating but the wiring resistance was so high that almost no current was getting through. Checking all connections, positive and earth return, is the first move.
I have started engines many times with a screwdriver across the solenoid and it has never failed. It sounds like the starter motor may be seized.
 
My local yanmar dealer seems to be charging £533:
129698-77010 starter motor 3JH3E & 4JH3E

Yes, that's a Yanmar original one from Yanmar. If you zoom in on your picture, you can just about make out the label that says "Hitachi" on it, which tells you who actually makes that original one.

Now you go on the Googles and type in stuff like yanmar "129698-77010" starter site:.uk

Or just go on eBay. You can find cheapo ones for around 70 quid: Starter Motor For Yanmar S114-815 S114-817 129608-77010 129698-77010 | eBay
Or original Hitachi nes for about 200 (well, from Germany in this instance - might find a UK supplier with more patience than me): Starter Starter YANMAR 3TNV88 KOMATSU Genuine Hitachi S114-815 2YM15 3JH3 3TNE88 | eBay

That is the same one you can buy from your Yanmar dealer for 2.5x the price.

For a spare, I happily carry a cheapo one, cause it does work and if you don't trust it, you can always repair the original one later and swap it back with the spare.

Back to your diagnosis, does the engine turn at all (ratchet spanner on the crankshaft with power off)? If so (and that didn't dislodge it) and since there's clearly enough amps to vaporize screwdriver tips arriving there, I'd say it's the starter motor itself. So take it off and heed above tips about brushes. Then comes the point where you think about extracting the rotor, not befoer :)
 
I have changed my starter on a Yanmar 4JH2 a couple of times.

There are considerably cheaper ones than the Yanmar one availabe from Delco and Bosch. And as others have mentioned above probably from elsewhere.
These days it might not be worth the cost of dismantling to change bushes etc - if you are replacing with a non Yanmar priced part.
 
If you shorted across the main solenoid terminals and power was seen to pass ( meaty spark and damage to screwdriver) then its more than likely the motor brushes are sticking. If your motor looks like that in no 4 ( pre engaged) and it didn't spin ( just the motor , not the engine) while you shorted the terminals then the above is very likely. A useful though not conclusive test is to give the motor case (towards the back end) a good 'rattle' with a hammer or some such which often encourages the brushes to slide forward in their holders and so make good contact. Then try the key and see if it works again. On the plus side the fact that the motor works occasionally is a good sign as the windings etc must be intact for it to work at all and what your looking for is a bad connection by and large.
That is my experience.
 
Having been stuck in a far flung place with a burnt out starter motor (old story due to wife getting ignition key ‘stuck’ in energise that I’ve just about got over…) and having to wait a week for a replacement, I now carry a spare starter motor (and alternator!).

As has been said above, they can be obtained for a fraction of the price of a Yanmar dealer (mine cost me about £100).

I still have the old one and mean to take it to the starter motor hospital but haven’t got around to it yet.
 
Having been stuck in a far flung place with a burnt out starter motor (old story due to wife getting ignition key ‘stuck’ in energise that I’ve just about got over…) and having to wait a week for a replacement.
Been there and done that.
And being a slow learner, have done that twice.
 
will be trying more of the suggestions here today. all contacts now squirted with contact cleaner. I'm guessing this isn't a fuse thing given that it was intermittently not working before failing completely.

There seems to be a lack of genuine Hitachi S114-817As (a "brand new" one on eBay from a small scale seller seemed rather pitted when looked at close up): I'll give LRE as suggested by Boater Sam a ring tomorrow.

Call me an electrical dunce but one thing that confuses me: measuring the voltage between the battery terminal on the starter and ground after turning the engine battery off I noticed that it took a few minutes to come down to zero. I know I should know this but what's with that?
 
one thing that confuses me: measuring the voltage between the battery terminal on the starter and ground after turning the engine battery off I noticed that it took a few minutes to come down to zero. I know I should know this but what's with that?

Capacitor somewhere on the engine side. Might not be obvious and quite small, like inside the tachometer or some such.
 
will be trying more of the suggestions here today. all contacts now squirted with contact cleaner. I'm guessing this isn't a fuse thing given that it was intermittently not working before failing completely.

There seems to be a lack of genuine Hitachi S114-817As (a "brand new" one on eBay from a small scale seller seemed rather pitted when looked at close up): I'll give LRE as suggested by Boater Sam a ring tomorrow.

Call me an electrical dunce but one thing that confuses me: measuring the voltage between the battery terminal on the starter and ground after turning the engine battery off I noticed that it took a few minutes to come down to zero. I know I should know this but what's with that?

Inverter is full of big capacitors.
 
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