If this is the same bike on Guam, I'd think the main item to look for is salt corrosion.
Especially the electrical connectors.
Use dielectric grease and coat all the connectors including the battery terminals.
Prevents corrosion and lubes the connectors. Great stuff.
Allow the bike to reach operating temperature before riding.
Otherwise you may foul those expensive iridium plugs.
If stock, change the final drive ratio. Go with a 15/41, 42, or 43.
It'll be much better at take off from stop lights.
Do routine maintenance and use good quality oil.
I myself use Mobil-1 4T 10W40 full synthetic. Others have their own preferences.
If you use the green (ethylene glycol) radiator coolant, change the coolant every two years. It becomes acidic and will start to eat the aluminum.
Otherwise, the RC51 is a very reliable engine.