just tuned up and summerized my 19' fiberform including new impeller kit.motor running hot.no flow from rear of vp 270 outdrive.impeller was wasted.removed thermostat.no flow at all.how far before and after seawater pump should i look for impeller pieces to cause obstruction.is there anything in lower unit to check.never had issues in previous 5 years except for basic maintenance and annual impeller kits.salt water cooled mostly in chesapeake bay.