Sounds like you need a new wear ring. Impeller could be dinged up also, if it is you get can get redone for a lot cheaper than a new one. One yours just disconnect ball joint of VTS link rod. Loosen 2 screws each side of trim ring and remove the nozzle. Disconnect steering cable from nozzle before removing venturi. Remove 4 retaining screws and withdraw venturi. Loosen 4 nuts and remove flat washers and lock washers from jet pump housing. Wiggle the jet pump a little as you pull it off.
Check your wear ring clearance with the impeller, clearance should not exceed 1.0 mm. To get the impeller off you will need a special impeller removal tool. They are not expensive and you can order one if you find you need a new wear ring.