Radiator flush before replacing coolant?
# How often? The makers of the long life coolants If I remember right are saying something like "five years or 100,000 miles."
# In my cars if changing I usually run a can of radiator flush thru before, run engine hot for ten minutes, drain, flush with distiled water, then refill with the coolant-distilled water mix.
But with the Rotax 912 not having the same convenient easy-opendrain valve at lowest point of cooling system as the car does on the radiator, etc.,that procedure (the several drain, warm up,and refill operations) would be a bit of a PITA.
So my question is, is the flush-cleaner additive step recommended strongly, mildly, not-at-all, or perhaps even frowned on?
For what it' shorthand, our old coolant although 2+ years old looks perfectly crystal clean and normal color..... To me suggesting a cleaner-flush additive step is not necessary.
Opinions from you more Rotax experienced folks?
Al