Check for loose wires, then most likely a bad coil or rusty mag maybe bad cdi or stator
The correct spark plug for this model is the NGK B-7ES.
The spark plug gap for a 1974 Yamaha DT125 is typically set at 0.6 to 0.7 mm (0.024 to 0.028 inches). It's essential to check the gap before installation to ensure optimal engine performance and ignition efficiency. Properly gapping the spark plug can help prevent misfires and improve fuel combustion. Always refer to the owner's manual for the most accurate specifications.
1974 yamaha dt 125
The point gap on a 1974 Yamaha DT125 is typically set to 0.3 mm (0.012 inches) when checking or adjusting the ignition points. This gap is crucial for proper ignition timing and engine performance. It's important to ensure the points are clean and functioning correctly to maintain optimal spark and engine efficiency. Always refer to the service manual for specific instructions and tolerances.
i am pretty sure it is 1974
One at a time
1974
Could be a bad "u" joint, or may your driveshaft isn't balanced.
The paint code for a 1974 Yamaha TY 250 is generally referred to as "Yamaha Red," which is often identified by the code 3B1. However, specific variations may exist depending on the model and production run. It's always best to verify with a Yamaha dealer or restoration guide for the most accurate information.
2 cycle.... since it a 2 stroke
champion j4c
what is the calibration of the spark plugs in a forklift clark 4 cyl. 1974