April 8, 20242 yr Yamaha ty175 Just had full engine rebuild but can't get it to spark. Coil / plug works as tried on another bike and has seperate earth wire from coil to engine, so it's got good earth. Points open, condensor is new. Flywheel is magnetic, new woodruff key How can I test generator/ ignition coil. When I use multimeter from black wire to earth I get 1.6ohms . Getting same on a spare unknown ty windings.
April 8, 20242 yr You can use your meter on continuity test setting to test your points for resistance and for timing when they close or open. TY175 has 2 stator coils, one dedicated to spark and the other for lights, all coils should have measurable low resistance of just a few ohms. Spark ignition coil will have measurable continuity resistance as well as the spark plug wire lead and cap. The voltage output from the stator ignition coil is non-regulated alternating current in excess of 6 volts and best tested with an oscilloscope.
April 8, 20242 yr I would replace the points if you haven't done so already, they have a habit of going on strike even though they look OK. This generic fault finding chart may help : Fault Finding Chart for Motorcycle Electrical Systems.pdf
April 9, 20242 yr Have you set the points gap correctly? If the points don't open properly the condensor will not build the charge to then spark.
April 10, 20242 yr Author Points are opening and closing and making continuity when testing manually.
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