* Model Variation: There were multiple YZ models in 1980 (YZ80, YZ125, YZ250). Each model had its own recommended fuel/oil ratio.
* Engine Condition: The fuel oil ratio can be influenced by the condition of your engine. A well-maintained engine might need a slightly different mix than one that has higher wear and tear.
* Usage: If you're racing, you might choose a different fuel/oil ratio than you would for casual riding.
Where to find the correct information:
1. Your Owner's Manual: The most accurate information will be in your motorcycle's original owner's manual.
2. Yamaha's Website: Search Yamaha's website for your specific motorcycle model. You might find a service manual or other documentation.
3. Local Motorcycle Shop: Talk to a mechanic at a reputable motorcycle shop. They will be familiar with your model and can advise on the appropriate fuel/oil ratio.
Important Note: Always use high-quality, pre-mixed two-stroke oil designed for your motorcycle. Using the incorrect oil or ratio can severely damage your engine.
