Bought this quad used about months ago had around my back yard with no problems at all. 1st time i took it out and did some hard riding it shut down on me about 30 minutes into the trip while riding in a shallow stream. I waited about 30 seconds and it started right back up. I never heard the fan come on and didn’t notice the dashboard flashing HOT. It rode fine for about another 20 minutes then sputtered like it wanted to shut down but never did then i took it back home. Since then i have installed a new thermostat, a new thermistor, and a temperature gauge with a fan bypass switch. I got the engine up to 195 degrees today and still no fan. When i use the switch to manually turn it on it does its job and cools the engine pretty quickly. I have 2 questions that hopefully someone can answer.. 1. What is the cause of the fan not turning on itself? and 2. If i manually control the engine temperature by turning the fan on and off as needed will it still cut out or will i be ok? What actually tells the engine to shut off? and incase you are wondering, Yes this quad was under the ecm recall and it was replaced.