Ok folks i got a couple questions. I don't know much about boats so please be patient. I but the muffs on the gills of the lower unit turn water on the started it let her idle for a few min and temp read 200. I replaced the tstat and tried it again same thing. I have been reading that it may be the impeller. Now my question is does anyone know where this is located at and how hard it it to change it. Also while on the muffs isn't there supposed to be water coming out of the lower unit. If so where from. Thanks in advance for your help.