Yamaha's YZ 250F is an off-road motocross dirt bike first released 21 years ago. Since its first model, which featured a four-stroke engine, a steel frame, and an aluminum subframe, it has undergone many changes (including an electric starter in 2019). It has also been lauded for its power (courtesy of the four-stroke engine) and good handling.
But in recent times, this motorcycle has come under fire for the problems it has caused bikers due to its inability to start. In this article, we'd be looking at possible reasons why Yamaha YZ 250F bikes have trouble starting.
Reasons For Yamaha YZ250F Starting Problem
- Expired fuel
Fuel used by four-stroke engines like the YZ 250F lasts for just 90 days when stored in a plastic tank. When these 90 days are up, the fuel expires and starts decomposing. The decomposed fuel now clogs the accelerator's pump circuit, which affects the bike when starting. If not tackled early, the decomposed fuel could also burn out the motorcycle's spark plugs, this being another issue altogether. The clogged pump circuit and burnt plug can ultimately result in a stuck clutch and many other issues.
In the case of this problem, you'll need to drain the decomposed fuel, refill, check and replace your spark plugs (as the case may be) and your clutch; then, your bike should be good to go.
- Air filter issues
Blocked air filters result in bikes that won't start. Bikes need air, so if a rag is blocking the air filter, sand, mud, or any blockage of any kind on the air filter, or even a leak in the airbox, your bike goes nowhere. It is important to make the short time required to check your air filter part of your pre-use bike maintenance routine so you enjoy a nice start.
- Flat battery
Bikes with electric starters, like recent models of the YZ 250F, use batteries to power their electric starter, so if the batteries are low or outrightly flat, the bike won't start. An indication of this situation would usually be a clicking sound from the battery, signaling a much-needed charge or replacement.
In the first place, Yamahas are notorious for their weak batteries, so this is a very likely situation in most YZ 250Fs. To solve this, you can either charge the battery, replace it, or buy a battery tender. Battery tenders are the preferable option because they are cheaper than new batteries, and they don't overcharge batteries like chargers, thereby retaining the battery life of your motorcycle.
Final notes
Many other reasons why your bike may not start, whether cold or hot, like faulty carburetor, low compression, faulty chokes, etc., but you must try to check and maintain some of the most important parts of your bike, especially before and after use. And when these parts are beyond maintenance, replacement should be the next thing on your mind.
About the authors
The CarAraC research team is composed of seasoned auto mechanics and automotive industry professionals, including individuals with advanced degrees and certifications in their field. Our team members boast prestigious credentials, reflecting their extensive knowledge and skills. These qualifications include: IMI: Institute of the Motor Industry, ASE-Certified Master Automobile Technicians; Coventry University, Graduate of MA in Automotive Journalism; Politecnico di Torino, Italy, MS Automotive Engineering; Ss. Cyril and Methodius University in Skopje, Mechanical University in Skopje; TOC Automotive College; DHA Suffa University, Department of Mechanical Engineering
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