The sx65 new updated model.    New crankshaft, ignition , clutch and other parts to update the sx65.   On the Dyno the power is lower than the 2023 engine,  but rejetted the 2024 revs a little higher than the 2023.   Its really hard the make the 2023 engine much better , as the engine has made great power. .  Random  cylinder issues, powervalve issues,  bottom end problems, strange vibrations in some.  Carby needle still not matched well, no surge washer etc.    The rotating crankshaft and clutch mass has been increased in the 2024, which slows down accelleration rates ,   so it is possible to make more power from a 2023 older model than a 2024 model.  All things considered , 2024 is still a nice 65.   For those who find the new LONGER brisk spark plug hard to purchase, you can modify your head very easily,  or use the VHM 2023 head with a std 2023 spark  plug.     You can also  buy the long spark plug in NGK here in Australia too.