Yamaha's are a bit cold blooded. Determine if it's compression, ignition or fuel. If your compression is good, next try a shot of starting fluid into the air cleaner, only use a bit and shoot some in while turning the starter or have someone shoot some in and kick it over immediately. If it starts or at least shows some life, your problem is in the fuel supply or carb. 60% of troubles I see is due to modern day crappy gas. Never use fuel with alcohol (oxygenated) and do not use gas more than 90 days old unless it was treated with a stabilizer.
Next step is check your spark. I prefer using an old spark plug gapped wide, say .040, and clamp it with a hose clamp to a battery charger alligator clamp to ground to the engine. You should see a consistent blue spark. If you have electric start, spin the motor for say 30 seconds and feel the heavy positive that goes to the starter, or the heavy ground. If it feels warm and/or if your starter doesn't smoothly turn over, a bad starter can take power away from the ignition.
Apr 16, 2014 |
2006 Yamaha Ybr 125