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
D7 with no spark
Avatar
carlg92
Birmingham
Second Gear User
Site Member
Forum Posts: 5
Member Since:
October 2, 2019
sp_UserOfflineSmall Offline
1
November 8, 2019 - 12:36 pm
sp_Permalink sp_Print

So finally got the v5c in my name. I called dvla 4 weeks after sending off the old old logbook they told me theres was no notes or a current owner for that vehicle so she told me to send off a v62 and do a historical tax change when at the post office with a v112. The post office lady couldn't change the historical tax class because the v5 was not in my name. But when the v5c came I sent it off with v112 and changed the colour. While waiting for that I de-rusted fuel tank, cleaned carburetor with new gaskets. Put the new battery in was shocked to see the lights worked including the brake light. Took the spark plug out to check for spark there was nothing. Cleaned the points with some dry wet and dry. Still no spark. Cleaned main trans loom wires to earth point as well as the rectifier earth to find a broken wire (WHITE) looking at a wiring diagram seeing that it goes to the points getting my hopes up after a quick repair. No spark. Any ideas where to start to find out what's the problem. Screenshot_20191108-124053_Gallery.jpgScreenshot_20191108-124103_Gallery.jpgScreenshot_20191108-124045_Gallery.jpgScreenshot_20191108-124036_Gallery.jpgScreenshot_20191108-123045_Gallery-1.jpg

Avatar
mikef
Chatham Kent
Club Technical Advisor
Committee
Forum Posts: 813
Member Since:
September 30, 2011
sp_UserOfflineSmall Offline
2
November 8, 2019 - 3:45 pm
sp_Permalink sp_Print

Hi Carl.
     Well, we don't have a lot to go on to be honest. Looking at your photos, it's a 1966 D7 twin switched.
The fuel tank is from an earlier D7 and the fact that the lights work from the battery is suggesting that the wiring, or part of it is from the single switched D7.
Those block connectors on the wiring suggests that some mods have been done. I see a separate ignition coil hanging on the frame.
Do you know how it is wired? Have you ever seen it run in it's present state.
Sorry to ask so many questions but we really need to know exactly what you have.
A photo of the generator stator would be a start. The twin switched and single switched generators were very different.
On a 1966 D7 the headlight should only work with the engine running.
Regards.

       Mike.

Avatar
carlg92
Birmingham
Second Gear User
Site Member
Forum Posts: 5
Member Since:
October 2, 2019
sp_UserOfflineSmall Offline
3
November 8, 2019 - 4:44 pm
sp_Permalink sp_Print

Okay I dont really have much knowledge on electrics but from the wiring diagram I can see on the bike that the wires are correct by colour up to certain points like the rear lights and the rectifier and a couple of mods behind the headlight. Both switches do work aswell as the switch on the bars.

I have not seen the bike running but was told by the previous owner it ran befor it was garaged around 10 years ago. IMG-20191029-WA0027.jpegScreenshot_20191108-163950_Gallery.jpg

Avatar
Sponge
Lancashire (A chip shop somewhere near Preston)
Top Gear User
Club Member
Forum Posts: 154
Member Since:
November 6, 2016
sp_UserOfflineSmall Offline
4
November 8, 2019 - 5:40 pm
sp_Permalink sp_Print

No spark - either a failed component or a bad / wrong connection - but which one - suggest start at one end and work your way through it methodically. 

There area a couple of wires hanging out of the generator bottom left - what are these ? Not normal to see wires there so they may be significant   

Also the points seem to be 'on the cam',  but the contacts themselves do not seem to be open -  a trained, expert, eye could probably solve this in a few minutes. I would suggest inviting another club member over to have a look.  

Regards

Sponge

Avatar
cocorico
Central France
Top Gear User
Site Member
Forum Posts: 3125
Member Since:
June 23, 2013
sp_UserOfflineSmall Offline
5
November 8, 2019 - 6:06 pm
sp_Permalink sp_Print

As a start, I'd suggest you disconnect  the front and rear of the loom from the ignition system and battery, then connect the battery through a simple switch and fuse to one side of the coil, the other side of the coil to the points. Then if you switch on and kick over you should get a series of healthy sparks from the plug. If you haven't a handy switch, use a croc clip or something you can disconnect quickly, just in case. If you get no spark, you need to check the points, spark plug, plug connector, HT cable. If you get a spark, you can then reconnect the loom and see if you still get a spark. If not, check the loom and especially the switch on the headlamp. You don't need to connect the rectifier yet, as there should be plenty of charge in the battery. Once it's running you can reconnect the generator, though I would change that old Selenium rectifier for a modern Silicon one. Might be worth considering a rectifier / regulator and even a conversion to 12V negative earth - the information is on the forum. hope-that-helps

1956 D3 running, lights to sort. 7 other bikes in the Barn, including a Morini 250 now insured and on road testing.

Avatar
mikef
Chatham Kent
Club Technical Advisor
Committee
Forum Posts: 813
Member Since:
September 30, 2011
sp_UserOfflineSmall Offline
6
November 9, 2019 - 7:09 am
sp_Permalink sp_Print

I can see from the photo of the generator that it is the correct one for a twin switched D7. Which is good news.
In the first instance I think Concorico's suggestion is good to test the ignition components.
Long term I think your best option is to replace the wiring loom, new ones are available. Your existing loom has obviously been modified and has many suspect connections.
The headlight on a twin switched D7 is powered directly from the generator and will only work with the engine running.

Regards
     Mike.

Avatar
carlg92
Birmingham
Second Gear User
Site Member
Forum Posts: 5
Member Since:
October 2, 2019
sp_UserOfflineSmall Offline
7
November 9, 2019 - 7:24 am
sp_Permalink sp_Print

I'm thinking about getting a new loom would this make it more simple and if I was to convert it to 12v at the same time will I have to modify any wires or is it as simple as switching some wires to different places. 

The wires hanging out the bottom left are where i think a horn was connected directly to the battery as the wires on the main loom for the horn (violet) are disconnected both behind headlight and down by the battery holder also the speedo bulb was not connected aswell as the earth. 

 

Thanks for the guidance and advice. I will be buying a new loom but still deciding on 12v conversion I may run it 6v see how it goes then decide. Can anybody tell me which loom I need. 

Carl 

Avatar
mikef
Chatham Kent
Club Technical Advisor
Committee
Forum Posts: 813
Member Since:
September 30, 2011
sp_UserOfflineSmall Offline
8
November 9, 2019 - 8:17 am
sp_Permalink sp_Print

You have many choices.
As your bike is not running, the ignition components are unknown, the wiring loom is probably beyond repair and you want to convert to 12V. It maybe worth considering a CDI system. Expensive but reliable and gives you new components. I have included a link below to the Electrex World version, there are others, Bones for example.

** Please log in to view **

If you want to keep the existing electrics and fit a new loom then these are available from many sources, I have included a link to one on e-bay as an example. See below.

** Please log in to view **

To modify the existing generator to run 12V is not too difficult but you will need to purchase a rectifier/regulator and you will lose the benefit of the emergency ignition function.

Just some ideas.
                 Mike.

Avatar
sunny
Norfolk
Top Gear User
Club Member
Forum Posts: 1322
Member Since:
January 9, 2013
sp_UserOfflineSmall Offline
9
November 9, 2019 - 10:45 am
sp_Permalink sp_Print

it  looks  like  the lose  of  spark   is  down  to the   batery , points & coil wiering   ect   <<  its   nice  to  see   the  correct   cam   ,points  &  wiering  loon  # harnes  even  if  the   it  has  been  cut  about    ,,  NONE   OF  the   3   difrant    wiering   loons / harness    fited  to   the   D 7  modle s     LETS    the  HEADLAMP   lite up    UNLESS   the  engin    is  RUNING      the   only   thing s  i  change   is  the  wypac  HT  coil   to  a 6  volt   J A P  coil    &  rectyfier  from  a  honda   or  alike  any  uther    upgrade       is  unnesasery    its   how   pepal   servis  the  sistem   that   maters     so  have fun     &   keep  the  teapot  going   &   if   your   keeping   to   the   2  swich   wypac   sistem    you  MUST     get  the   CORRECT     LOOM /HARNES  or mack  one     as  i always   do    without   an  E start  on it   

Forum Timezone: Europe/London

Most Users Ever Online: 223

Currently Online:
9 Guest(s)

Currently Browsing this Page:
1 Guest(s)

Top Posters:

Cornish Rooster: 3314

Anderzander: 3208

bart: 3135

cocorico: 3125

Sprung Chicken: 2651

Mags 1: 2612

David Dale: 2485

Munchkin: 2231

Blue Heeler: 2138

Katj: 2138

Newest Members:

_2223

Forum Stats:

Groups: 9

Forums: 46

Topics: 12106

Posts: 104197

 

Member Stats:

Guest Posters: 518

Members: 3728

Moderators: 3

Admins: 3

Administrators: Piquet, JMD, Rusty Floater

Moderators: xcgb, Mick W, Stoo63