Engine Fire/burnt out starter motor

Hi Aidan
[ QUOTE ]
Incidentally, when I ran the engine for 40 mins before the second outing the engine wouldnt shut off by using the key. It turned out the start battery had been (incorrectly) shut off after starting (alternator should still output through the VSR?) , and the ignition couldnt stop the engine. When the start battery switch was turned on again it worked ok. I dont know if this throws any more light on the matter.

[/ QUOTE ]
That I'm afraid totally confuses me.

It may be that the "ignition" switch is in an even worse state than peviously supposed or that the "stop" system is not how I assumed it to be. I assumed that there would be a solenoid operated valve in the fuel line which opened when the solenoid was energised and closed again when de-energised, just like the arrangement in a car. I suppose a motorised valve is possible, operated via a relay like a motorsed valve in a domestic central heating system, with the supply coming fom the starter battery. That it beginning to sound very improbable though, unnecessarily complex and heading for a situation where you can't stop the engine in the event of a toatal electrical failure (In which case there must be an emergency stop mechanism somewhere. There is one any way on the CAV injection pump on my Peugeot car but there was not as far as I ever discovered on the Bosch system old the old Fiesta.)

May be it is the ignition switch that is at fault and that switching the battery back in was just a coincidence.

I have to admit I don't know the answer to this one without access to a wiring diagram, but I would definitely still take a good look at the switch. Perhaps connect a voltmeter (or a bulb) to the solenoid energising wire before connecting up the new motor and make sure that every time the switch returns from the 'start' position it does truly break that connection.

It does sound from "all the components are green with corrosion" that the electical system could do with a bit of refurbishment but I guess the complete panel and loom are not going to be cheap.

I do hope you have not also damaged the alternator by disconnecting the battery, that really would be unfortunate. Provided the VSR had switched the other battery in it probably saved the day. I'm glad I have been able to to do all my serious sailing in a boat maintained out of someone elses pocket, even if I've helped do a lot of the work.

Vic
 
Hi All, just a note to put this (old) thread to rest. Many thanks to all who offered help and advice on my Bukh starter problem.

I did eventually replace the starter motor on my DV20 for a brand new one, along with a new engine panel and wiring loom. After connecting it all up, it's been running fine .... and the old starter motor has been sitting forlorn in my garage ever since.

I got an email recently from a local Fulmar owner (John MacRae) with a another Bukh DV20 Starter Motor problem, and looking to salvage the drive/pinion from my old one. After some email contact we sorted out delivery of the old starter and John has managed to salvage the bits he needed. John has an engineering background and seems familiar with motors... so I thought I'd post some feedback from our email conversations.

[ QUOTE ]
Solenoid was fine, despite blackened appearance.Pinion perfectly OK as well. For the motor to have burnt out in the way that it did, BOTH pinion andsolenoid would have to have failed - the solenoid disengages the pinion,but even if it didn't, the pinion contains a sprag clutch mechanism whichwould prevent the engine driving the starter. Therefore the only answer is that the igition switch must have been sobadly corroded that the ignition switch spring action failed and thestarter continued to turn until it burnt out. Any old ignition switchwill do of course - I used an old land rover one when I was adjusting thevalves, it saved jumping in and out of the cockpit ever time I wanted toturn the engine over - just temporarily bypassed the engine panel. Theland rover one has a really strong spring in it - no danger of the startergetting stuck on!

[/ QUOTE ]

John goes on to say
[ QUOTE ]
Incidentally, I was doing some googling around and discovered that you can actually buy replacement field coils for the bukh starter. So byreplacing the field coils and with a land rover ignition switch ..... you could have been back in business. none of which helps you now of course. and it wouldn't eventually havehelped us either!!

[/ QUOTE ]

John sent me a PDF page from the catalog with the replacement field coils. He points out that it's the same as that from a Porsche 911.... no wonder BUKH parts are so expensive if theyre making them using Porches bits!

The supplier's website is http://www.iat-usa.com. ... hope it can be of some use to anybody else with similar problems. (Thanks John for the feedback...... and the fine bottle of Talisker !)

[Edit]: ..... on this page http://www.iat-usa.com/parts.html
go to Catalog... then "Replacement Starter Field Coils".....
then "IAT #: 06114".....
 
Thanks for reporting back on that. Nice to know I was getting somewhere near the mark.
Reading through it all I noticed one contribution said something like "just to add my thoughts" and then got it in one!.

One thing I have learnt since then is that the engine does not shut off in the way that the car does. IE by de-energising a solenoid valve that is energised to allow the engine to run.. When you switch off you have to turn the key back beyond the off position to a stop position. Correct? That energises a stop solenoid that cuts off the fuel.

This means that in the event of an electrical supply failure, very unlikely I guess, you would not be able to stop the engine with the key. There should be an emergency stop lever on the injection pump. It would be advisable to know its location if you don't already.

I imagine that it is designed like this so that if necessary you can hand start the engine without having any power available which you would not be able to do if you had to energise a solenoid valve to open it. It doesn't matter with a car, if it won't start you just get a taxi home!
 
Vic, came across this old thread when searching a different BUKH starter issue (I will start a new thread if necessary).

There is no manual stop as such on the BUKH..........but it's easy to stop using the decompressor lever if necessary. It certainly WAS necessary when my stop-solenoid burned out! (taking the wiring with it incidentally). In similar vein to this thread, it was the control panel that caused the failure. The ignition switch is not biased in the 'stop' position, and relies on an alarm to warn you to turn it back to off. Unfortunately the alarm circuit is notoriously unreliable.

Fortunately a obtained a replacement from another formurite who was breaking an engine (BUKH wanted £200 + VAT). I have now also added a heavy duty press switch!!

Vic
 
[ QUOTE ]
There is no manual stop as such on the BUKH

[/ QUOTE ] I don't know why I thought there was. They tell you not to stop the engine using the decompression lever because damage to the valve and lifting mechanism can result. I suppose it's OK to use it to start the engine because it will only be turning slowly but if you are using it to stop the engine its running more quickly.

A good case for having an accessible fuel shut off valve perhaps.
 
You must log in or register to reply here.

Share this page

Top