For a 2000 Yamaha YZ 250, the air-fuel mixture needle is typically set around 1.5 to 2 turns out from the fully seated position. However, the exact setting can vary based on factors such as altitude, temperature, and modifications to the bike. It's always best to consult the owner's manual or a professional for specific tuning guidelines. Adjustments should be made gradually while testing the bike's performance for optimal results.
Start at 1 1/2 turns from seat and adjust for best idle
Try 1.5 turns out on the mixture screw for an initial setting.
40:1 is a good mixture.
50:1
Here's a general rule of thumb: Close the fuel mixture valve, then back it out 2 1/2 turns. Then adjust it from there. It's a good starting point, and usually works for me.
1 and half to 2 full turns
Turn it all the way in and then back out 1 1/2 turns
Three turns out from all the way in will get you close
Rent a Ktm Bike with endurobikes.co
Check for fuel and spark.
Start at 1 1/2 turns from seat and adjust until you get the best idle
You need a spark, a fuel / air mixture supply to have combustion in the combustion chamber.