Perkins 4107 starter motor wiring info wanted

[jack2]

Hi,

I have just bought an old Senior 31/ project 31 that I am going to save from extinction!

It is on dry land and has been there for a number of years.

There has recently been 12" of water inside and one of the perkins 4107 has been partially dismantled.

 

I have got the "good" engine turning by using a screwdriver on the flywheel teeth and seems to be ok.

-After a had removed the injectors, filled the cylinders with hot oil and filled the engine with diesel and left it over night!

 

The starter, an SL189 perkins 13 tooth inertia starter motor I think seems to have 2 wiring connectors both the same at the rear.I will have to strip this down as well but it also turns but will be damp.- When I try a battery on either connector I get a short. Should there be 2 soleniods per starter? and does anyone have a wiring diagram of the circuits of the boat?

 

I would like to get one engine running and then I can put it on the water if necessary so any help will be great!

Thanks

 

 

[Sir Nibble]

The two terminals on your starter are +ve and -ve. One goes to the solenoid controlled +ve and the other to B-. If you have a short from these terminals to the casing then you have an internal short in the starter, possibly the brushbox more likely the field coils. This is an M418 type starter made by uncle Joe Lucas and you should be able to source a scrap one off a landrover with decent field coils if need be.

[The Bagdad Boatman (waits)]

The 4107 has wet piston sleeve liners in the block. if these rust then pinholes appear. there are two o-rings at the bottom and 4 leak tell tales in the side if the engine.

[Geoff Taylor]

Hi, This model starter should be operated via a solenoid and the positive go to the insulated pin on the motor and other pin to neg. (easy to check polarity with multimeter ). Trying to jump the motor direct will result in a lot of sparks even if ok. I have a 4108 Perkins in our boat and have the pre-engaged type motor of which I personally prefer as it is more powerful than the inertia type and kinder to the starter ring.

Edited October 6, 2013 by Geoff Taylor

[Tony Brooks]

The insulated stud is (from memory) insulated by a nylon or paxalon sleeve in an over-sized hole plus an insulated washer or flange on either side of the end plate. It is all too easy to lose these if you are not familiar with such things so make sure they are there. Its usually the brass stud for the live (I am not going to say positive because some boats of that age were wired with the negative insulated and positive return.

 

I have exceptionally occasionally had shorts caused by a build up of brush dust and damp on the insulated brush holder mounts some strip, clean and a few days in the airing cupboard would not come amiss.

[Sir Nibble]

Take it to bits, what's to lose?

[jack2]

Hi All,

Thanks for your help.

I have taken both starters to bits and cleaned them with diesel to loosen the rust and gunge, then with petrol, and now waiting for them to dry out and see what happens.

One of them had BOTH screws at the rear touching the body, so I have removed the unused one and will make sure the other is Isolated. - I think that is one of the reasons he sold the boat! - That and many of the other faults still to find!

 

- Something about known unknowns and unknown unknowns is springing to mind.

[Geoff Taylor]

Hi, Using petrol to clean the motor parts will dissolve the shellac varnish on the armature windings and probably render them useless, I would if they were that bad exchange them for recon units which should not break the bank and give reliable service for quite some time.

[Sir Nibble]

Hi, Using petrol to clean the motor parts will dissolve the shellac varnish on the armature windings and probably render them useless, I would if they were that bad exchange them for recon units which should not break the bank and give reliable service for quite some time.

Good job nobody has used shellac for a very long time then.

[Geoff Taylor]

Good job nobody has used shellac for a very long time then.

 

Bearing in mind the starter motors could be the same age as the engines (up to 50yrs old) it is possible I may be right!!

Edited October 9, 2013 by Geoff Taylor

[Tony Brooks]

 

Bearing in mind the starter motors could be the same age as the engines (up to 50yrs old) it is possible I may be right!!

 

Yes but in those days we still washed both starter and dynamo bodies out with petrol, blew them out, put a rag in them to wick liquid away and the next day kept them warm with no rag to finally dry them. We then re-coated the fields with shellac. I can not remember a single field failure. Mind you I was an apprentice at the time so did what I was told. I think that today I would use brake cleaner rather than petrol because if there is any signs of "oil" left after the job it is only likely to attract brush dust.