Alternator swap 1998 model

[His Dudeness]

That's just a manufacturer's spec for that "F4T359/MITSUBISHI magneto". Have a look in your Haynes at the testing the charging system section. It'll say something like the battery should be around 12.5V with the bike switched off and around the 14.3V at 5000RPM like you're getting. There's no problem with your bike. If it was overcharging and putting out say 17V at idle it'd would probably be the regulator/rectifier that was at fault not the alternator.