Gents-
Kinda ran out of patience with the factory plastic scuppers that seem to act like a pump that runs backward.
I tried duck bills, one way valves made for commercial fish tanks along with the cheap stock scuppers.
I found these aluminum scuppers made for jet ski's. You have to slightly cut the bottom of the scupper to make it match up to the level of the 215 cc.
So far it is working well. They are expensive about $90.00 each. But I save that on frustration.
http://www.247innovations.com/pwc/products.htm
Monty Walker