You can still get the OEM parts from most Yamaha dealers! They will probably have to order most parts. Or you can look online. there are many sites that sell the OEM parts. I own a 1984 XT600 and I've had no problems finding parts.
I hope this helps you!
The fork pressure on a Yamaha XT600 typically ranges from 10 to 15 psi, depending on the rider's weight, riding style, and specific suspension setup. It's important to consult the owner's manual or a professional mechanic for the recommended settings tailored to your specific model and riding conditions. Adjusting the fork pressure can significantly affect handling and comfort, so make changes gradually and test the bike's performance after each adjustment.
The fuel ratio for the Weed Eater XT600 is typically a mix of 50:1, which means 50 parts gasoline to 1 part two-stroke oil. It's important to use high-quality two-stroke oil specifically designed for air-cooled engines to ensure optimal performance. Always refer to the owner's manual for the most accurate and specific recommendations for your model.