any recommendations on that ?
Ayuh,...... What I do is disconnect the lines at the manifold, under the outdrive, 'n lift, 'n lower the drive, by hand a few times to purge the rams,....
Then hop into the boat, fill the tank with fresh oil, 'n cycle the pump up, 'n down, til clean oil is expelled into the catchcan,.....
After that, hook everything back up, refill the tank, 'n cycle it full up, 'n full down, 1/2 dozen times to bleed the air outa it,.....
Top off the tank again, 'n Go Boatin',......