Originally posted by cmscat50
@Sep 22 2005, 01:50 PM
Guys, on the 600HO the radiator is only for warmup. Once the thermostat opens the radiator is completly bypassed. It is just dead weight during normal operation.
When Polaris went with the Dual Loop cooling system a few years ago, they went from a bypass type thermostat, to a two stage cooling system. They also increased the size of the 'bypass' outlet in the head, because it is really no longer a bypass circuit. It is a 3/4" NPT thread that goes to a 1" hose.
Some of their diagrams still use the 'bypass' terminology, but that is misleading.
on the 600 HO Fusion, the first stage, always flowing loop has got the radiator only. When the machine is sitting still, this will allow the motor to warm up even in very cold weather. When the thermostat opens up, the front bulkhead, running board and tail exchanger are in the second stage loop.