{"nhtsa_id":10176884,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2020-07-02","date":"2020-06-30","document_id":"M2020-006","mfr_campaign":null,"replaces":null,"component":"ENGINE AND ENGINE COOLING; FUEL SYSTEM, GASOLINE; EQUIPMENT","mfr_system":null,"summary":"Certain 2020 YZ250FX Models - Rich Running Condition - ECU Reprogramming Some units may experience a condition where the engine is hard to start due to a fouled spark plug. The 2020 YZ250FX’s ignition timing and air/fuel ratio were set to meet this model’s target of good low speed torque for off-road closed-course competition. When riding in certain conditions, the slightly retarded ignition timing and richer air/fuel mixture may lead to the spark plug fouling, causing a hard-starting condition. To remedy this condition, Yamaha has revised the ECU programming to address the rich running condition.","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2020/MC-10176884-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2020/MC-10176884-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/10176884","components":[{"id":"engine","name":"Engine","parent":null},{"id":"equipment","name":"Equipment and accessories","parent":null},{"id":"fuel-system","name":"Fuel system","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"YAMAHA","model":"YZ250FX","year_from":2020,"year_to":2020,"match":"exact","vehicle_ids":["2020_yamaha_yz250fx"]}],"as_of":"2026-10-19","note":"A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.","attribution":[]}