I ordered an impeller for my 9.8a Nissan outboard. When I got to the point of changing it it would not fit over the drive shaft. I contacted iboat, talking to a Peter and Julie, They was to get me an Return athorization Number so It could be returned. Iboats poolicy was within 2-3 business days. I have Not received the number yet, 10 days passing. In waiting I found the problem with the impeller, the drive shaft outside diameter is.575, the inside diameter of the impeller is also .575-not wonder it would not fit. I am not so upset about the part, made by Sierra, as I am about trying to gert the impeller returned and my money refunded. I will more the probably not be ordering anything else from iboat. Bill