Flush Evinrude Sportsman lower unit

[15evie]

I have an Evinrude Sportsman 4425 1.5hp that needs gearcase oil replaced! I've drained some of lower unit oil(gunk in picture), but cant seem to get rest of gunk out of there as it's really thick! Would gas or mineral spirits run through top hole work to clean all of it out of there? Or those not advised! I've tried regular 10/30 motor oil to no avail! After drained could I run a pressure test(for leaks) with vacuum pump in pic, or is there another way of doing that?

 

[15evie]

 

[SuperT]

If it were me, I'd use diesel fuel to flush. Then refill and drain the oil, then refill again.

 

[15evie]

Thank You, I'll try some Diesel fuel in there!

 

[joereeves]

Mineral Spirits is what most of us use to clean parts when we're working on engines.

A lower unit that small... if the diesel oil doesn't do the job, and if it were me... I'd remove the lower unit, fill it halfway or 3/4 with mineral spirits, then shake it violently. If that doesn't clean it, nothing will.