Racing 4 stroke spark plug for 2020-25 KTM 350 EXCF / XCFW / XFW

 
This plug is from the 2025 KTM 350 /450 SXF.  You can se by pic 2, that the new plugs electrode and porcelin insulator, don't extend as far as the stock EXC plug on the left.
     The stock extended plug, is what we refer to as an "emissions" friendly plug.  Extending the electrode starts the combustion sooner, and therefore completes combustion sooner.  Problem is, when you pump up the power 30%, like in the case of using one of the power bundles, you chance craking the thin, extended porcelin.
    This is why the race bikes, don't use this type of plug.  The heat range is the same, but the porcelin won't crack.  If it does crack, the bikee will run erratic and idle poorly.
    You should change the plug every 50 hours or so, to keep your bike running it's best.