Bike dont start. Yamaha 175 CT - 1973 make.

Put bout an inch in each

Hi, is this a points ignition or cdi, does he have a spark at the plug? An engine needs three things to run, spark,fuel, and compression, was the engine from the same year and model, maybe the engine has cdi, and the bike is fitted with a points ignition setup?

sounds like the problem is your battery is not charging when you are riding. The most common cause is a faulty regulator / rectifier. Contact a motorcycle wreckers for these parts, or your yamaha dealer.
Easy way to test is, when your bike is running, and the lights start to dim, before the bike shuts down, using a volt meter, test the voltage at the battery terminals, should be about 14V. If faulty rectifier,no charge going in to your battery, then the reading will be low, about only a few volts. If you dont have a volt meter, then any mechanic shop can do this test for you. best to have this done before buying any parts.

I haven't worked on that bike in 30 years, but as I recall, the black wire goes to the points. The coil grounds via the mounting bolts.

Why mix thev gas ,your problem could well be down to a carb or air problem.