I just got a 1975 40 hp 40RL 75 -c I have a generic clymer manual but the photos are junk I cannot make out where the t-stat is supposed to be, I also looked at Marineengine.com and there pics were no better & the parts list does not list a t-stat so, please straight 'N me out here.. got the old motor purring like a kitten but no water coming out so impeller is on the way, but I want to check/replace the t-stat if needed. thanks