Yanmar 4JH2E Impeller

I just replaced the impeller in my IP 40 with a spare left on the boat by the previous owner. The spare was Yanmar PN 129470-42532 which had 9 blades. I have been looking on-line for a source to purchase replacements but many show a pict of the impeller with 12 blades. 1) Should I ignore the pict and order the PN, 2) has there been a design change that uses a 12 blade impeller in the same pump, or 3) do I need to upgrade the pump to use a 12 bladed impeller? These impellers are very pricey and I want to get it right.

Thanks,

Clay Showen, owner of Lone Star, an IP 40

I'd ignore the picture. If the impeller fits snugly then use it. Then check the perfromance...
If water comes out the exhaust , and you dont overheat
You are good to go!

Thanks. I found a local Yanmar repair shop in Cocoa and purchased the part number. I has 9 blades. I now have several spares.