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Ruston & Hornsby 3VRH not starting. Battery or cable problem.


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I have got a problem with my Ruston & Hornsby 3VRH engine. It won't start.
It's been repainted and was to be taken to a mooring today. I'm not there ands can't be there because I'm in a quarantine hotel in London. They ran the engine for a couple of hours yesterday and it ran fine: started fine, ran smoothly. Oil level is fine, coolant is fine.
However, today, it just wouldn't start and after trying a few times, the battery was flat (measuring 12.02V)
They got a forklift battery and hooked that up to the starter motor. The engine still didn't start.Tried a new car battery; same. It seems the cables heated up massively.
I'm told it felt like the cables weren't large enough for the power being delivered.
 
This engine has had a few starting issues in the past, requiring a blowtorch but I've never had a problem (although I've not owned it long). I suspect that it's more to do with the battery and cables. But my knowledge of boat electrics and batteries you could write on the back of a postage stamp and still have room for a Jamie Oliver recipe. 
 
The battery is a Numax XV31MF 12v 105 Ah 925 MCA. I don't know how old it is but at least 2 years.
 
Any thoughts among the wise old heads here?
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If the cables are heating up massively current  is going somewhere.  What size are the cables? The crimped lugs have 2 numbers on.  The first number is the cable size.  Should be 25 or preferably bigger. 

Is the starter motor turning the engine over? 

What is different between yesterday when it ran and now?

 

The battery should be big enough.

 Make sure it is fully charged- voltage at about 14.4 V and current at 5 A or less and holding  steady for an hour. If the final current is higher than 5 A or the voltage will not get to 14.4  the battery has expired.

 

Check all the cable connections are tight.

Check the engine turns over freely by hand with the decompressors in.

If if turns over on the starter is there white smoke from the exhaust?  Absence of smoke =lack of fuel.

N

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Well without volt drop readings I would not like to say what it is. It could well be a starter fault with one of the two brush pairs not making contact or a short circuit. If anything prevents a starter reaching its designed speed t will draw massive amounts of amps and that can cause volt drop on the normally correctly sized cables.

 

Fault finding for volt drop here http://www.tb-training.co.uk/MarineE06.html#PRE-ENGAGE STARTERS

but I would also like a current reading (amps).

 

 

 

 

 

 

 

 

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1 hour ago, BEngo said:

If the cables are heating up massively current  is going somewhere.  What size are the cables? The crimped lugs have 2 numbers on.  The first number is the cable size.  Should be 25 or preferably bigger. 

Is the starter motor turning the engine over? 

What is different between yesterday when it ran and now?

 

The battery should be big enough.

 Make sure it is fully charged- voltage at about 14.4 V and current at 5 A or less and holding  steady for an hour. If the final current is higher than 5 A or the voltage will not get to 14.4  the battery has expired.

 

Check all the cable connections are tight.

Check the engine turns over freely by hand with the decompressors in.

If if turns over on the starter is there white smoke from the exhaust?  Absence of smoke =lack of fuel.

N

 

1 hour ago, Tony Brooks said:

Well without volt drop readings I would not like to say what it is. It could well be a starter fault with one of the two brush pairs not making contact or a short circuit. If anything prevents a starter reaching its designed speed t will draw massive amounts of amps and that can cause volt drop on the normally correctly sized cables.

 

Fault finding for volt drop here http://www.tb-training.co.uk/MarineE06.html#PRE-ENGAGE STARTERS

but I would also like a current reading (amps).

 

I am trying to get more information but I appreciate the input so far. I am 80 miles away stuck in a hotel and relying on third parties.

 

There's a sense that this might be as simple as the battery expending so much effort yesterday that two hours running wasn't enough to put much charge back in the battery.

The this morning, the first few failed cranks used up the last of the power.

 

I was told the engine was turning over but not firing, with a feeling that the engine wasn't turning quite fast enough to fire.

 

Then with the jump batteries, the long jump leads were too long and not thick enough and so there was heat build up.

 

I'm going to get an engineer to have a look in the next few days and probably get a new battery in. I see that the Numax gets quite good reviews from boaters here.

 

I will follow the fault-finding stuff on your website, Tony, thanks.

 

3 minutes ago, Tracy D'arth said:

Is there a stop control that has not been fully returned?

 

No, we don't think so. I admit we are a bit puzzled by why there was so little juice in the battery this morning. And as I wasn't there (I'm holed up in a maximum-security quarantine hotel so I'm having to go by what others tell me ?). Maybe it's a combination of things, cold start, low battery.

 

My other half has suggested hitting it with a spanner while swearing at it. "That's what you do with everything else".

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If your charging system is working 2 hours running should easily have put enough power back into the start battery for the next start.

 

If the start battery was in a good enough state to start the engine when it hadn't run for some time, then there should have been no problem the following day. 

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I am wondering if an alternator diode has failed allowing a 24/7 discharge or someone left the ignition on all night.

 

I agree 2 hours should have put the starting load back into the battery if the alternator is working properly.

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36 minutes ago, David Mack said:

If your charging system is working 2 hours running should easily have put enough power back into the start battery for the next start.

 

If the start battery was in a good enough state to start the engine when it hadn't run for some time, then there should have been no problem the following day. 

 

It hadn't been run for more than a month I think. (I can't be sure - I work overseas)

43 minutes ago, Tony Brooks said:

I am wondering if an alternator diode has failed allowing a 24/7 discharge or someone left the ignition on all night.

 

I agree 2 hours should have put the starting load back into the battery if the alternator is working properly.

 We will check the alternator.

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3 hours ago, stort_mark said:

 

It hadn't been run for more than a month I think. (I can't be sure - I work overseas)

 We will check the alternator.

 

For that we need the charging voltage after several hours charging or the charging current and alternator rated output asap after the first start of the day.  Make sure its not warm first thing in the morning as well.

Edited by Tony Brooks
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4 hours ago, stort_mark said:

 

It hadn't been run for more than a month I think. (I can't be sure - I work overseas)

 We will check the alternator.

Mine sat all through out the lockdown and cranked hard with no problem, more than a month. Are you sure there was no drain.

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Hi,

The batteries in Cypress are just 2 years old, the engine starts well normally, but it's not a 'quick turn of the key' starter, it'a vintage job! and needs some respect, It's dead easy to flatten the battery by just turning it over without any thought and cables do become hot under these circumstances.

 

I would not let anybody have a go a starting it without some thought and instruction. That engine needs careful use of the de-compression lever, easy starting on that engine is achieved by using the lever to decompress the engine, turning it over a few times with the starting handle, then turn it over on the starter motor getting revs up, then throw the decompression lever and away she goes.

 

Sometimes, with that engine a blast from a blow torch helps, it's a good engine that one, but takes a knack to start it, it sounds as though the 'numpties' trying to start it have not got the experience and just keeping a digit on the starter button will not get it going, doing that will just flatten batteries and heat up cables.

 

The charging system was modified to overcome problems a few years ago, it now has 2 alternators and a Battery management system, and the engine had new pistons and a through overhaul at Watford some years ago.

 

Letting anybody loose on a vintage engine, even down to trying to start it is not recommended.

 

It's a difficult times for engines and batteries, my 2LW started perfectly, after lockdown, but the batteries needed renewal.

 

Hope this helps.

 

Mike

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Is the excess fuel toggle on the injection pump set?  This  is usually needed for a Ruston  cold start. If the engine can be turned over by hand (decompressed) the injectors should make a noise., if they don't, there is a lack of fuel or the speed control and/or excess  fuel toggle are not set to max.

 

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4 minutes ago, billh said:

Is the excess fuel toggle on the injection pump set?  This  is usually needed for a Ruston  cold start. If the engine can be turned over by hand (decompressed) the injectors should make a noise., if they don't, there is a lack of fuel or the speed control and/or excess  fuel toggle are not set to max.

 

Interesting, and well worth following up, on that engine you can actually feel the individual injectors 'doing their job' through the pipes.

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On 10/05/2021 at 09:13, LEO said:

Hi,

The batteries in Cypress are just 2 years old, the engine starts well normally, but it's not a 'quick turn of the key' starter, it'a vintage job! and needs some respect, It's dead easy to flatten the battery by just turning it over without any thought and cables do become hot under these circumstances.

 

I would not let anybody have a go a starting it without some thought and instruction. That engine needs careful use of the de-compression lever, easy starting on that engine is achieved by using the lever to decompress the engine, turning it over a few times with the starting handle, then turn it over on the starter motor getting revs up, then throw the decompression lever and away she goes.

 

Sometimes, with that engine a blast from a blow torch helps, it's a good engine that one, but takes a knack to start it, it sounds as though the 'numpties' trying to start it have not got the experience and just keeping a digit on the starter button will not get it going, doing that will just flatten batteries and heat up cables.

 

The charging system was modified to overcome problems a few years ago, it now has 2 alternators and a Battery management system, and the engine had new pistons and a through overhaul at Watford some years ago.

 

Letting anybody loose on a vintage engine, even down to trying to start it is not recommended.

 

It's a difficult times for engines and batteries, my 2LW started perfectly, after lockdown, but the batteries needed renewal.

 

Hope this helps.

 

Mike

Hi Mike,

I was going to get an email put together for you and Jim, mainly to show the fabulous paint job Chris has done. But this has rather taken over this week!

 

The engine was started fine on Saturday and ran for a couple of hours, but failed to start on Sunday morning. The whole job (from picking up at Cowroast to getting up to Stretton Stop, painting and this) happened while I was in Ethiopia so everything had to be explained from a distance and I know they had a good chat with Darren before leaving.

 

I think they've started the engine many times with no problem so it's been a surprise for all of us a bit.

 

I'm going to put a new battery in Friday and see whether it's as simple as that (I suspect not). There's been some good suggestions here, but I'm having to work from memory and photographs.

 

Thanks,

 

Mark

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Mark,

 

Have sent you a PM and email. if you have survived 10 days quarantined in a hotel at Gatwick and engine trouble you deserve a break.........hope she fires up.

 

Mike.

Day Tank Full?

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21 minutes ago, LEO said:

Day Tank Full?

That's a very good point.  There  is no sight guage on the day tank and it has to be filled from a small electric pump - easy to forget.

 

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NB Cypress has been restored to life. Thank you to all for your extremely valuable help.

 

I decided to call RCR who were extremely helpful and after co-ordinating no less than five parties (me, RCR centre, RCR engineer, person with key to the boat, person with key to the wharf), all the planets lined up Friday morning: a new Numax XV31MF with freshly baked cranking power ("You could restart Chernobyl with that"), carefully timed button pushing and a swing of the lever and she started up.

 

So it was goodbye to the friendly folk at Swan Lane Wharf and we then floated off to Hinckley, stopping after three minutes to retrieve a builder's rubble bag that wound itself around the prop. The very last bridge (#17) removed the 'splitter' on the exhaust (sure there's a technical term) but a lovely days' cruise. If I hadn't been a bit pressed for time, I'd have gone down to the basin, one of my favourite places on the network.

 

As always when entering a strange marina for the first time, there was a huge socially-distanced audience and the still air turned into a gale force northerly, and I successfully demonstrated my party trick of manoeuvring a boat backwards and forwards to no effect.

 

The only negative part of the day was the "That's some tickover" comment from the sour-faced canal guru at Bridge 5, who was barely tied up at the visitor mooring. The 3VRH has quite a fast note, and because Cypress swims so quickly (with no wake, no wash), I usually give her a burst of reverse and then take it out of gear when going past moored boats but that does - for a short time - increase the engine speed. 

I was so stunned by his sarcasm, all I could do was turn to look at my zero wash and wake, and ripple of a bow wave and shake my head. But at least I had a further hour to think up witty and cutting retorts.

 

But again, thank you all for your helpful advice and commentary. We don't know the exact cause of the problem, but plan to do a bit more diagnostics.

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