A A A
Avatar

Please consider registering
Guest

Search

— Forum Scope —






— Match —





— Forum Options —





Minimum search word length is 3 characters - maximum search word length is 84 characters

Register Lost password?
sp_Feed sp_PrintTopic sp_TopicIcon
1961d7 ignition coil
Avatar
Charlieb
Second Gear User
Club Member
Forum Posts: 12
Member Since:
January 25, 2021
sp_UserOfflineSmall Offline
1
February 7, 2021 - 7:19 pm
sp_Permalink sp_Print

Just started working on my 1961 d7 it as a wipac 55 geny marked 1704 it has 2 lighting coils and 1 charging coil and 1 ht coil,i have checked all the wiing diagrams and it all seems to be wired correctly.it is a single light  switch on the headlamp,to get a spark do you need to have the battery connected.i have owned a bantam before about 40 odd years ago i think the ht coil must be broken as the plug and points look okay i think someone as played about with it in the past

Avatar
mikef
Chatham Kent
Club Technical Advisor
Committee
Forum Posts: 987
Member Since:
September 30, 2011
sp_UserOfflineSmall Offline
2
February 7, 2021 - 8:32 pm
sp_Permalink sp_Print

Hi Charlie.
             I think that at some time in the past the coils have been swapped on your generator. Originally the 1704 generator would only have had the 3 coils on it. The ignition coil would have been fitted under the seat. That was the later D7 with 2 headlamp switches.
As you now have 4 coils on the stator you have magneto ignition and it would not require a battery to obtain a spark.
If the HT coil is an original (brown in colour) then there is a good possibility that it could be faulty. Normally the secondary winding goes open circuit. A good one reads about 5KΩ from the HT connection with respect to the earthed wire.

Mike.

Avatar
Charlieb
Second Gear User
Club Member
Forum Posts: 12
Member Since:
January 25, 2021
sp_UserOfflineSmall Offline
3
February 7, 2021 - 8:58 pm
sp_Permalink sp_Print

hi Mike

          Thanks very much that is what i thought itis the old brown one do you know how the lighting and the charging coils should be wired for the single switch d7 bantam by the engine and frame numbers its a 61 d7

Avatar
mikef
Chatham Kent
Club Technical Advisor
Committee
Forum Posts: 987
Member Since:
September 30, 2011
sp_UserOfflineSmall Offline
4
February 7, 2021 - 10:20 pm
sp_Permalink sp_Print

Hi Charlie.
       The single switched D7 is a bit of a mystery to me to be honest. I am told that there are 2 different versions, although I have only ever encountered one and I think it is the most common. This is the battery lighting version all of the lights work from the battery and the generator coils are switched in as needed by the lighting switch.
The second version uses AC lighting for the headlamp, so it will only work when the engine is running. This version uses the outer bottom coils for the headlight and the centre bottom coil is used to charge the battery via the rectifier.
The version that you have will be dependent on the wiring loom fitted and how the generator is wired.
The best thing to do in the first instance is to have a good look at the generator. Is one end of all three coils connected together?
If the answer to that question is yes then the generator is for the battery lighting version.
I can draw a picture of how the coils should be wired if need be.
I have attached a wiring diagram of what I consider to be the most common D7 single switched wiring diagram. See how it compares with the loom that you have fitted.
D7-Single-Switched.jpg

sp_PlupAttachments Attachments
Avatar
Charlieb
Second Gear User
Club Member
Forum Posts: 12
Member Since:
January 25, 2021
sp_UserOfflineSmall Offline
5
February 7, 2021 - 10:36 pm
sp_Permalink sp_Print

Hi  Mike 

           thanks my loom is a coplete mess and it needs a new one ive loked at the generator wiring and it apears to have coils 1 and 3 wired together and coil 2 wired on its sugesting that it has 2 coils for lihgting and 1 coil the bottom one coil 2 for charging the battery i was thinking about having ie refurbished but wondered how the coils should be wired

Avatar
Charlieb
Second Gear User
Club Member
Forum Posts: 12
Member Since:
January 25, 2021
sp_UserOfflineSmall Offline
Avatar
Charlieb
Second Gear User
Club Member
Forum Posts: 12
Member Since:
January 25, 2021
sp_UserOfflineSmall Offline
7
February 8, 2021 - 12:04 am
sp_Permalink sp_Print

Hi Mike have posted pics of my coils and stator I know the wiring of the stator is wrong so I have now reversed it

Avatar
GlenAnderson
Dover
Top Gear User
Club Member
Forum Posts: 411
Member Since:
August 27, 2013
sp_UserOfflineSmall Offline
8
February 8, 2021 - 11:10 am
sp_Permalink sp_Print

The original coil wiring was done in such a way as to minimise the requirements of a base-model machine needing what were, at the time, very expensive electrical components that would push the price of the bike up. To avoid having proper regulation and rectification, capable of dealing with the entire potential electrical loads on the bike, the factory instead followed a method of using a coil that would generate only enough power for its load - hence one pair of coils to provide lighting power, and another one that would trickle charge the battery through a very basic rectifier and no regulator at all. These days, with simple, cheap and very reliable full wave and fully regulating rectifier/regulator units, there’s no reason whatsoever not to simply wire all three coils together in series and use the generator’s full potential. 

Avatar
mikef
Chatham Kent
Club Technical Advisor
Committee
Forum Posts: 987
Member Since:
September 30, 2011
sp_UserOfflineSmall Offline
9
February 8, 2021 - 2:48 pm
sp_Permalink sp_Print

Hi Charlie.
      Unfortunately this is where things start to get confusing. I have been looking at several diagrams from Wipac for the single switched D7.
All depends on how your stator is wired. I have attached a picture of a version of the  AC headlighting wiring diagram below. In the bottom right hand corner it shows coils 1 and 3 wired in series with the ends connected to pins 1 and 2 of the stator. The trickle charge coil (2) connects between pins 3 and 4 of the stator.
As you have a wiring loom that is a mess and an unknown stator it maybe worth considering the CDI option, just a thought. You may be determined to get to the bottom of what you have though.
Mike.

ACheadlight.jpg

sp_PlupAttachments Attachments
Forum Timezone: Europe/London

Most Users Ever Online: 223

Currently Online: stubaker58, Sponge
13 Guest(s)

Currently Browsing this Page:
1 Guest(s)

Top Posters:

cocorico: 3465

Cornish Rooster: 3109

bart: 2691

Blue Heeler: 2540

David Dale: 2346

Sprung Chicken: 2292

Piquet: 1975

Mags 1: 1853

sunny: 1807

jess steele: 1672

Newest Members:

Boneidle

Forum Stats:

Groups: 9

Forums: 48

Topics: 11261

Posts: 99724

 

Member Stats:

Guest Posters: 1433

Members: 3269

Moderators: 0

Admins: 3

Administrators: Bantam-Super, JMD, Stoo63