Although it was advertised as fitting a 2014 YZ250F (even stated on packaging it was for a YZ250F 2014. The timing plug (small top one) was very difficult to fit, it appeared as though the thread pitch was different to the timing cover. Thankfully both cover and plug are soft alloy so I was able to cut a new thread with a little patience, I eventually got the plug done up tight. Time will tell I guess if it seals OK. Bottom plug fitted perfectly with no hassles.