OK cool. I'll have to look into the rectifier.  I was wondering because I was thinking about installing a cooling fan for the radiator

Cooling fans has been a hot topic on some of the other forums recently.  Your stator will not generate enough power to run a cooling fan when the engine RPMs are low.  Adding a good sized battery would provide power for the fan when speeds are slow as long as the low speeds are not continuous for more than a few minutes at a time.  If you putt around for a few minutes with the fan running you will need to run the engine at medium to high RPM without lights for 2 to 3 times the time the fan was on to re-charge the battery.