I hit the sandy bottom on Lake St. Clair twice Monday. There was no damage; I was going slow with drive trimmed up but stuck the bullet in the sand pretty good. This is an Imco shorty with the inlet right in the front bottom. I have a standard sea strainer not meant to catch sand. I also have a 525 with closed cooling. Everything seems OK but are the passages inside the heat exchanger, p/s cooler, oil cooler and fuel cooler large enough to pass fine sand? I have a SS raw water pump and it will get a new impeller in the spring.

it should pass through, but I would do some flushing of the heat exchanger and coolers when you do the impeller change. You can use an infrared temp gun to make sure there are no hot spots while the motors are running at speed.

Thanks. I usually disconnect some of the hoses when winterizing to be sure all water has drained. Backflushing the coolers is not too hard. I do carry an infrared temp gun to keep an eye on oil temp.