Took my dad's jet sled with a 90/60 Mercury jet out last Sunday and managed to suck up some rocks into the intake. The grates are all bent, so it allowed some golf ball sized rocks to get in. One of the rocks lodged in the impeller area, which prevented the motor from turning over, so I took the grate off the bottom and put a crescent wrench on the main nut and turned it until the rock popped loose. After getting all the rocks out of the motor, I noticed it's only got about half the "get up and go" it had before. The impeller blades are noticebly dull and dinged up. Not sure what they looked like before the rocks were sucked up. The housing around the impeller(s) is/are noticeably grooved.

I'm thinking I should take the impeller(s) off and file the edges and put them back on. Are the impeller edges most likely the problem, or is there something else I should be concerned with? Thanks for any help!