Bought a used 2013 that probably sat for years. Looked perfect though. At around 100 miles, I had starting issues. Since I don't want to take my 2013 cbr 250 apart right away,. to check for spark I spray "quick start" starting fluid into the air filter. If it starts, it's probably clogged fuel injector. You can clean it. see you tube. Now, what I did to prevent this from happening again is I took the tank off, replaced the filter, after market(around $8.00) , took off the fuel pump, cleaned it and now it's reliable, smooth and perfect. Even gets better mileage. If you don't use it regularly, or get poor quality fuel, you may need a fuel preserver and a fuel injector additive to keep it running. I bought a new battery thinking it was that, but not so simple.