facebook1 youtube1 twitter1 instagram google plus linkedin1 pinterest1

logosmallNOTICE:  If you are not a free registered member of the site, you will not see the photos in the forum, and you won't be able to access our premium member content. Please consider joining our community!

Welcome, Guest
Username: Password: Remember me
  • Page:
  • 1

TOPIC: 1972 Yamaha CT2 175 - Ignition Assembly

1972 Yamaha CT2 175 - Ignition Assembly 12 Sep 2018 11:40 #1

  • CKO21
  • CKO21's Avatar Topic Author
  • Offline
  • Newbie
  • Newbie
  • Posts: 4
  • Likes received: 0
Hi All,

New to bikes and just started working on a 72 CT2. The Ignition Assembly (Where you put the key in) was falling apart and I found an original unused assembly to replace it with. Used to be able to turn the lock with a screw driver or even a penny to turn it on. I've installed it but now I can't get the headlight, taillight/brakelight and directionals to all work at the same time. When I turn the key to the first position the directionals work when I turn it to the second position only the headlight and tail light work. Is this normal? Is it a battery issue? Any advice is greatly appreciated.

Please Log in or Create an account to join the conversation.

1972 Yamaha CT2 175 - Ignition Assembly 12 Sep 2018 15:05 #2

  • RT325
  • RT325's Avatar
  • Offline
  • Collector
  • Collector
  • Posts: 3316
  • Likes received: 976
Too early in the day for me to think clearly lol but if you've fitted a second hand switch it's possible someone's had it apart to clean the contacts inside & reassembled it half a turn out. I think you get two shots at the internal bits with the plates that bridge the contacts so you'll either get it right --or wrong, sounds wrong. Been 45 years since being in one lol but think you have two screws on the underside, or 3 screws!!. Ignore me if i'm not reading your story right & others will weigh in soon. Cheers.
The following user(s) Liked this Post: CKO21

Please Log in or Create an account to join the conversation.

1972 Yamaha CT2 175 - Ignition Assembly 12 Sep 2018 15:12 #3

  • RT325
  • RT325's Avatar
  • Offline
  • Collector
  • Collector
  • Posts: 3316
  • Likes received: 976
also--being ct2 i dare say the lights are magneto not battery but not sure about tail light ion the usa, down here in nz tail light is magneto too. blinkers & stop light & horn--neutral light if fitted are battery, but if battery is flat the mag lighting coil will try to run them when motor running although with lights on and brake applied it;ll drag the lights down. also with a stuffed or empty batter you stand the chance of blowing the headlight at revs and a single wire regulator is a good update--bulb saving regulator that is. anyway--if it was ok prior to switch change then it sounds like a mainly switch issue--ok i'm outa here for the day. ps, guessing ya in the usa.
The following user(s) Liked this Post: CKO21

Please Log in or Create an account to join the conversation.

1972 Yamaha CT2 175 - Ignition Assembly 12 Sep 2018 16:30 #4

  • MarkT
  • MarkT's Avatar
  • Offline
  • Site Contributor
  • Site Contributor
  • Posts: 4327
  • Likes received: 1928
What country you are in matters... for the US with regard to lights:

In position 1, the brown and red (battery) connect which makes the flashers and horn work.

In position 2, the brown and red are still connected along with the blue (L) taillight wire. (This is because the US requires the taillight to stay on if engine dies.) The headlight only comes on with the engine running and is powered by the yellow (AC power from stator) connecting to another blue that runs the headlight and gauge lights. (In other countries this circuit also runs the taillight.)

Does your headlight come on without the engine running?

Here is a chart from the CT2 wiring diagram showing what wires connect in the different key positions. Full diagram available in service manual in Tech Library.

Attachments:
The following user(s) Liked this Post: CKO21

Please Log in or Create an account to join the conversation.

1963 YG1-T, 1965 MG1-T, Allstate 250, 1970 CT1b, 1971 R5, 1973 AT3MX, 1974 TS400L, 1975 RD350, 1976 DT175C, 1976 Husqvarna 250CR, 1981 DT175G, 1988 DT50, 1990 "Super" DT50, 1991 RT180, 2017 XT250

1972 Yamaha CT2 175 - Ignition Assembly 12 Sep 2018 20:10 #5

  • Mothersbaugh
  • Mothersbaugh's Avatar
  • Offline
  • Collector
  • Collector
  • Posts: 640
  • Likes received: 258

RT325 wrote: If you've fitted a second hand switch it's possible someone's had it apart to clean the contacts inside & reassembled it half a turn out. I think you get two shots at the internal bits with the plates that bridge the contacts so you'll either get it right --or wrong, sounds wrong.


More possibly, someone has inverted the plate in the switch that turns left and right. I had a CT-1 that was exactly backwards in how the unit worked, what it turned on, and the top plate was on upside down. Flipped it over, and everything worked as desired.
The following user(s) Liked this Post: Hammer, CKO21

Please Log in or Create an account to join the conversation.

1972 Yamaha CT2 175 - Ignition Assembly 13 Sep 2018 13:21 #6

  • CKO21
  • CKO21's Avatar Topic Author
  • Offline
  • Newbie
  • Newbie
  • Posts: 4
  • Likes received: 0
Thanks, I'm in the US.

Please Log in or Create an account to join the conversation.

1972 Yamaha CT2 175 - Ignition Assembly 13 Sep 2018 13:21 #7

  • CKO21
  • CKO21's Avatar Topic Author
  • Offline
  • Newbie
  • Newbie
  • Posts: 4
  • Likes received: 0
I'll try flipping the plate and see if it fixes the problem, thanks!

Please Log in or Create an account to join the conversation.

  • Page:
  • 1
Moderators: VinnieDEETyamadminDmanEnduronutMakotosunDevinJames Hart