2016 mercury 60 hp efi,are all t stats tested in hot to boiling water?

[stylesabu]

i have been away for quite some time. no boat issues. i have a 5 year old pontoon, that is mainly used to go 5-6 mph around lake 25 minutes at a time. i got it out of storage and first trip,alarm goes of. but everything seemed fine. checked owners manual it stated that was coolant temp or oil pressure. oil is changed every season, i bet i havent gone through 50 gallons of gas, yet. i bought it new.i have had problems with my old johnson 150 hp 2 stroke picking up sand in shallow water. so i pulled t stat. it doesnt open in 130 degree water 150, no i eveb went to 170. dont open.most auto t stat i could get to open,by 212, as long as they were severely overheated. do marine t-stat work the same why, mine looks like a mini t-stat. also any way to pull codes if it isnt a thermostat? Thanks, Kyle

 

[Chris1956]

Outboard t-stats open at 140*F or thereabouts. Sounds like yours is bad.

The other candidate is a waterpump rebuild. It would not be unusual if you picked up sand to chew up the impeller.