coolant Line Question

[speedunl2]

On the Hayabusa 1300 there is a 3/8" hose coming off the thermostat housing to the radiator. Is it a necessary bypass or is it okay to block it off?

[plkracer]

It's on top of the thermostat housing right, on the backside of the engine? Do not plug it! It's a vent for the thermostat so it doesn't get a bubble in it and not open due to the thermostat not seeing heat. It could lead to a fried engine. Make sure it goes to the top of your radiator, and has a semi-straight path, with no loops so it can vent any air to the top of the rad if necessary.

[Gene]

While the thermostat is closed during engine warm up the bypass is open for coolant circulation. It stays open as your thrmostat operates. It alo serves as a high-point vent. Do not block it off.

[speedunl2]

I dont have a port on the top of my radiator, any suggestions?

[plkracer]

Take it to a radiator shop and have them weld one in. I had them change all of mine to suit the engine. Worked out very well. You may also want them to add a thermostat bung for a fan switch if you don't already have one.

[Gene]

The thermo switch on mine is a fitting sandwiched into the radiator outlet/supply hose to the water pump. That's the temperature you need to monitor.