pugwash01
Member
Initially they said 'the diode' and then that 'the windings had gone - beyond repair'.
Burned out starter and alternator Yanmar 3YM30
- Thread starter pugwash01
- Start date
Saguday
Well-Known Member
We have a Yanmar 4JH3BE and 4 weeks ago had to replace both the alternator and the starter motor.
Apparent cause was moisture corroding the windings of both and I've since learnt that a known fault is the engine coolant leaking and dripping down onto both of these and over time corroding the windings.
That doesn't appear to have been the case with us we just seem (inexplicably) to have had a build-up of salty moisture-laden air in the engine compartment which did it's most expensive worst over a period when we were not using the boat (yes, we usually leave the access door off for ventilation).
Keep a close eye on it and check for coolant leaks carefully.
Apparent cause was moisture corroding the windings of both and I've since learnt that a known fault is the engine coolant leaking and dripping down onto both of these and over time corroding the windings.
That doesn't appear to have been the case with us we just seem (inexplicably) to have had a build-up of salty moisture-laden air in the engine compartment which did it's most expensive worst over a period when we were not using the boat (yes, we usually leave the access door off for ventilation).
Keep a close eye on it and check for coolant leaks carefully.
dom
Well-Known Member
Why am I not surprised: 'the diode has gone', notwithstanding the fact that there are three, is basically pub talk. But for clarity, and assuming that the windings were indeed found to be shot following a proper bench test, this would have had nothing to do with leaving the switch in the zero position.
I'm guessing this is now an ongoing dispute: as a matter of interest was it a UK charter, or somewhere abroad?
pugwash01
Member
UK and I think OK people. I just think an engineer has advised them badly.
<152587>
...
Notwithstanding you better have a re-count of diodes.
dom
Well-Known Member
I almost edited the post to include the fact that Noah ordered the diodes to enter two by two, where each pair acts ...:sleeping:
RichardS
N/A
Just to add to this interesting thread ...... my Son complained that his car (modern design so pre-engaged starter) was making a strange noise when he started it so I had a listen to it yesterday. There was indeed a rattling/squealing sound. The rattling lasted for a second or two once the engine had fired but the squealing continued for another couple of seconds.
OK I said, alternator belt too loose. We tightened the polyvee and the squealing's completely gone ..... but the rattling is completely unchanged. We tried starting with and without the clutch depressed but exactly the same. So out comes the 2-foot piece of 1/2 inch square timber and I press it to my ear and then a part of the engine and Son starts the car.
Alternator, water pump, steering pump all sound OK but pressing it to the starter motor seems to amplify the sound so the final test is to drive the car to the end of our drive, point it down the hill, engage 3rd gear and bump start. Total silence when the engine starts.
So I'm now 100% convinced that the starter motor overrun clutch is not releasing quickly enough. I've had a quick look on the web and this problem is virtually unheard of and I can only find two confirmed examples out of a zillion "rattling noise on starting engine" hits.
In both the web cases the cure was a new starter motor. However, I'm from Yorkshire and a new starter motor is off the agenda ..... so the starter motor is coming off today (unfortunately not a simple job on his Suzuki) and it will be fixed!
I'll report back later.
Richard
VicS
Well-Known Member
Just to add to this interesting thread ...... my Son complained that his car (modern design so pre-engaged starter) was making a strange noise when he started it so I had a listen to it yesterday. There was indeed a rattling/squealing sound. The rattling lasted for a second or two once the engine had fired but the squealing continued for another couple of seconds.
OK I said, alternator belt too loose. We tightened the polyvee and the squealing's completely gone ..... but the rattling is completely unchanged. We tried starting with and without the clutch depressed but exactly the same. So out comes the 2-foot piece of 1/2 inch square timber and I press it to my ear and then a part of the engine and Son starts the car.
Alternator, water pump, steering pump all sound OK but pressing it to the starter motor seems to amplify the sound so the final test is to drive the car to the end of our drive, point it down the hill, engage 3rd gear and bump start. Total silence when the engine starts.
So I'm now 100% convinced that the starter motor overrun clutch is not releasing quickly enough. I've had a quick look on the web and this problem is virtually unheard of and I can only find two confirmed examples out of a zillion "rattling noise on starting engine" hits.
In both the web cases the cure was a new starter motor. However, I'm from Yorkshire and a new starter motor is off the agenda ..... so the starter motor is coming off today (unfortunately not a simple job on his Suzuki) and it will be fixed!
I'll report back later.
Richard
Ive had "trouble" with one car for a number of years . Ghastly noise when started, but goes if clutch depressed. No noise if started with clutch depressed . Starter not disengaging is prime suspect but don't understand the association with the clutch ..... little bit of movement ... end float ??? ... perhaps.
I always start it, as per the owners manual, with foot on clutch so actually no problem.
I assume that just spinning the pinion , without the starter motor itself turning, could be the cause of the noise.
RichardS
N/A
I'd be very surprised if any end float could be serious enough to affect the starter pinion / flywheel alignment sufficiently to cause the noise. I suspect you'd have some knocking or oil seal problems if the float was that bad.
I think it's more likely to be some kind of slop in the thrust bearing or, more likely, the friction plate or springs. The latter could be allow some "flapping around" until the engine is running at which point the slop is taken up by the spinning crankshaft and doesn't rattle whilst the engine is running.
What happens if you freewheel downhill both in gear and in neutral and engage/disengage the clutch a few times before actually holding it long enough to start the engine? I suspect you might be able to reproduce the effect for a brief moment with the starter motor completely removed from the equation.
Richard
RichardS
N/A
In both the web cases the cure was a new starter motor. However, I'm from Yorkshire and a new starter motor is off the agenda ..... so the starter motor is coming off today (unfortunately not a simple job on his Suzuki) and it will be fixed!
I'll report back later.
Richard
OK .... the report is that we removed the starter motor and I tried to turn the pinion. It would not turn one way (due to the planetary gearing) and, guess what, it would not turn the other way either unless I levered against it with a screwdriver. I tested it against my "standby" battery with a pair of jump leads and the solenoid engages, the pinion spins ..... and then makes the graunching noise when the power is removed.
As the overrun clutch is not accessible without fully stripping down the starter motor, that was the next stage.
Almost the entire starter motor including the planetary gear set in the white housing is user serviceable ..... but the overrun clutch in the silver cylinder next to the pinion is not!
The pinion teetch were in good condition so it was worth spending the time to force white spirit into the housing and spinning by hand and repeating until clean white spirit was coming out. I've no idea whether these clutches are packed with grease or run clean but as it is not possible to break it open I was never going to be able to repack it anyway .... so I ran some thin engine oil into it until it started to come out from the other side and thereby lubricated the spiral.
We cleaned out and regreased all the bearings, repacked the gearbox, cleaned the commutator with meths and reassembled it. It now runs like a dream!
The moral of this story seems to be that pre-engaged starter motor overrunning clutches are very reliable and usually last a very long time ..... but when they do start to fail you do get plenty of warning!
Richard
lw395
Well-Known Member
The over-run clutch should not really have to do anything.
As the engine starts, it should turn the pinion faster than the starter wants to turn it, driving the pinion out of mesh along the Bendix.
It was a long time ago when I had a Moto Guzzi, that I last stripped a starter. I'm not sure it even had an over-run clutch, but its issues were mostly caused by wear and arcing in the contact set.
I discovered by trial and error that the contacts must be forcibly closed before the pinion limits the solenoid's travel. The Bendix will then ensure the pinion fully engages.
A game of filing and fettling, re-bushing the linkage. A new starter was a week's take home pay in those days.
In those days if a Guzzi owner gave you money, there would normally be a 50p piece with burnt edges, the most convenient tool for shorting the contactor!
Thinking about it, maybe the lack of over-run clutch caused the Bendix to fight the solenoid, causing the arcing as the bendix pulls the contacts slightly apart??
As the engine starts, it should turn the pinion faster than the starter wants to turn it, driving the pinion out of mesh along the Bendix.
It was a long time ago when I had a Moto Guzzi, that I last stripped a starter. I'm not sure it even had an over-run clutch, but its issues were mostly caused by wear and arcing in the contact set.
I discovered by trial and error that the contacts must be forcibly closed before the pinion limits the solenoid's travel. The Bendix will then ensure the pinion fully engages.
A game of filing and fettling, re-bushing the linkage. A new starter was a week's take home pay in those days.
In those days if a Guzzi owner gave you money, there would normally be a 50p piece with burnt edges, the most convenient tool for shorting the contactor!
Thinking about it, maybe the lack of over-run clutch caused the Bendix to fight the solenoid, causing the arcing as the bendix pulls the contacts slightly apart??
VicS
Well-Known Member
We are talking a bout pre-engaged starter motors They do not have a Bendix gear. It's inertia starters that have a Bendix
lw395
Well-Known Member
I may have been using the term a little loosely.
If you look in Richard's picture you can see the helix which is effectively a bendix gear exactly like an inertia starter.
If you jump the solenoid the motor will spin and the pinion will fly forwards just like in the old days of morris minors....
Maybe that's technically not covered by Mr Bendix's patent though.
There may well be pre-engage starters with straight instead of helical bendix-esque splines, I've never seen one, but these days I'm more selecive in what I take to bits.
Bikes tend to have 'sprag clutches' instead.
westernman
Well-Known Member
I have burned out two starter motors in that way. I had far to many keys on the bunch of keys for the engine, and the return spring from the start position to run position was a bit rusted. The key stayed in the start position, the starter stayed engaged and burnt out on both occasions. The first time it burst into flames.
The first time I ended up sailing in to Alcudia harbour (which the Capitainerie did not appreciate at all). But they were totally unwilling to even to reply to the VHF when I was just 200 yards away from the entrance.
RichardS
N/A
But Vic's point is that it is not the helix/spring which pushes the pinion forwards or pulls it backwards out of engagement, it's the fork from the solenoid which runs in the groove just behind the overrun clutch which physically pushes the pinion out and pulls it back in. There's no spring to do this like on a bendix starter.
I don't see why the helix wouldn't work with straight grooves as you suggest but presumably the spiral eases the meshing so it's less harsh. However, if it wasn't for the overrun clutch and the solenoid forks the pinion would never un-mesh as there would be nothing to pull it back away from the flywheel.
The overrun clutch is clearly important as if it isn't working correctly the noise is terrible.
Richard
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VicS
Well-Known Member
That is my understanding !
DownWest
Well-Known Member
I have had the over-run clutch seize on a pre-engaged starter. The remote solenoid stuck (as on the Yanmars above) and after the clutch failed, the starter overspeeded, burnt out and jammed. The flywheel ring gear 'machined' off the teeth on the pinion.
One wonders about the engineer who looked at the OP's charter boat. If he is trying to lay blame for leaving the switch at 0, then he might be throwing in a duff alternater for good measure. Leaving the key at 0, only turns off the exciter current. As several have posted, you need to disconnect the battery(ies) to blow the diode set.
One wonders about the engineer who looked at the OP's charter boat. If he is trying to lay blame for leaving the switch at 0, then he might be throwing in a duff alternater for good measure. Leaving the key at 0, only turns off the exciter current. As several have posted, you need to disconnect the battery(ies) to blow the diode set.
<152587>
...
OK .... the report is that we removed the starter motor and I tried to turn the pinion. It would not turn one way (due to the planetary gearing) and, guess what, it would not turn the other way either unless I levered against it with a screwdriver. I tested it against my "standby" battery with a pair of jump leads and the solenoid engages, the pinion spins ..... and then makes the graunching noise when the power is removed.
As the overrun clutch is not accessible without fully stripping down the starter motor, that was the next stage.
Almost the entire starter motor including the planetary gear set in the white housing is user serviceable ..... but the overrun clutch in the silver cylinder next to the pinion is not!
The pinion teetch were in good condition so it was worth spending the time to force white spirit into the housing and spinning by hand and repeating until clean white spirit was coming out. I've no idea whether these clutches are packed with grease or run clean but as it is not possible to break it open I was never going to be able to repack it anyway .... so I ran some thin engine oil into it until it started to come out from the other side and thereby lubricated the spiral.
We cleaned out and regreased all the bearings, repacked the gearbox, cleaned the commutator with meths and reassembled it. It now runs like a dream!
The moral of this story seems to be that pre-engaged starter motor overrunning clutches are very reliable and usually last a very long time ..... but when they do start to fail you do get plenty of warning!
Richard
Best you remove motor again and wash with brake cleaner, drive end of start motors are not lubricated. Prevents attracting clutch dust which will clog mechanism.
lw395
Well-Known Member
I think the helix keeps the pinion engaged while the motor is driving, particularly at first when the high current will have dropped the solenoid voltage to something a lot less than 12.But Vic's point is that it is not the helix/spring which pushes the pinion forwards or pulls it backwards out of engagement, it's the fork from the solenoid which runs in the groove just behind the overrun clutch which physically pushes the pinion out and pulls it back in. There's no spring to do this like on a bendix starter.
I don't see why the helix wouldn't work with straight grooves as you suggest but presumably the spiral eases the meshing so it's less harsh. However, if it wasn't for the overrun clutch and the solenoid forks the pinion would never un-mesh as there would be nothing to pull it back away from the flywheel.
The overrun clutch is clearly important as if it isn't working correctly the noise is terrible.
Richard
I seem to remember Bendix starters can make horrible noises too....
I've got a vague idea that some starters have a subtle way of using the solenoid to pull the gear out of mesh if the current reverses due to over-run?
RichardS
N/A
Ah yes .... best to do what you reckon the manufacturer did .... which led to the drive end of the starter motor mechanism becoming clogged.
As the manufacturer's only option is for me to buy a new part, it's best to trust my own engineeing experience.
Richard