Post By Simo
Ignition coil test 1968 CB175
Can anyone give advice, I've just started (when i say started i mean this is my first bike restoration ever and i started yesterday!!) doing up a 1968 CB175 K0 model. I want to test the condition of the ignition coil, i have removed it from the bike and tested the resistance of the primary wires (i think that's what they are called - smaller wires) and it reads about 4.7 ohms. I have then done a separate test between the two spark plug leads and they read about 14.7 k Ohms. Do i need to do another test?
Basically i'm a bit confused (not hard for a serious hack like me!!) as the youtube videos i'm watching seem to conflict in regards to testing the ignition coil between 2 ways, explained below:
1. test between primary leads (i got 4.7 ohms), and then a separate test between plug leads (as i explained above and got 14.7 k ohms); OR
2. test between primary leads (i got 4.7 ohms) and then a test between 1 primary lead and one plug lead (i get no reading - does this mean its cactus?).
I could take it to a shop but kind off busy working shop hours and also wheres the fun in that, the point of this project is to do it all (or as much as possible) myself.
Any advice greatly appreciated.
Your coil seems fine, the issue with the videos is that there are different types of coil.... So different ways to test them
The Cb175 use a wasted spark set up on a dual fire coil.
That means no continuity between the primary and secondary winding ( infinite resistance) nothing to read, which is what you get in test #2.
Be aware that
1. Youtube has no editors.... So any hack advice isnt taken down
2. Different bikes are, well different.... So a youtube video for setting the carbs on a GB500 is only helpful if you're working on a GB500
3. Even if you're watching a video about a cb175 sloper because of point #1. There's no garentee that the poster isn't showing you wrong, they might have watched the video on setting the gb500 carbs and then used that info on their Cb175 post.
Search the links here on Ht for a Fsm (factory service manual) instead
Thanks Simo appreciate the advice.