The Trailmaster 300cc go karts have an awesome and powerful liquid cooled engine. These engines are high performing and provide all the power and torque you could need. But with a radiator and coolant lines, there are extra steps you need to take for maintenance. Learn how to bleed the coolant lines on your Trailmaster 300 go kart.
Radiators on a liquid cooled engine
The radiator operates by pumping antifreeze though coolant lines, around the internal parts of the engine, and back to the radiator. The liquid absorbs excess heat from the engine, helping it to cool off. When the hot coolant pumps back into the radiator, its flows through the numerous fins that curve back and forth. As the liquid travels through the radiator, it passes a thermostat that read the temperature of the liquid.
How coolant stays coolant
When the thermostat detects that the coolant is above a certain temperature, it will switch the fan on. The fan will blow air over the fins of the radiator, removing heat from the coolant that is flowing through. This is “radiating” the heat away from the coolant. When the coolant exits the radiator, the temperature has been lowered enough for it to absorb more heat off the engine. It’s important to bleed the coolant lines to keep your Trailmaster 300 operating well.
![Trailamaster 300 go kart radiator for coolant](https://i0.wp.com/trailmastergokarts.com/wp-content/uploads/2024/05/300_XRX__30685-edited.jpg?resize=443%2C331&ssl=1)
Issues in your cooling system
This is an amazing system to keep your engine running cool and smooth. But chaos strikes if the system is not operating properly. The biggest issue arises when air bubbles get in the lines. Air bubble can do several things. The first is that an air bubble gets stuck around the thermostat sensor. The air bubble will remain cooler than the coolant, and will never trigger the fan to turn on. Your engine will quickly overheat when this happens.
Overheating alarm- what to do
Trailmaster 300 go karts are equipped with an overheating alarm and light. If the check engine light on your dash ever comes on with an electronic sounding alarm buzzing, stop your kart right away and let it cool off. You kart will most likely go into limp mode, where it loses most of its power and will not accelerate. You will need to bleed the air from the coolant lines before you ride again.
How to bleed coolant lines on your Trailmaster 300 go kart
1. Make sure radiator is full of coolant. Leave the cap off the radiator.
2. Find the hose that runs on the drivers side of the seats, past the battery. This a coolant hose that runs to the thermostat. This is the hose that tends to fill with air.
3. Carefully fill this hose with coolant to eliminate as much of the air as possible. Attach the hose back to the thermostat.
4. Remove vent screw from top of thermostat housing. NOT the screws that hold the thermostat on, but the vent screw on top.
5. Crank your kart and leave it running. Watch the coolant level at the radiator and reservoir and continue to top it off. You can squeeze all of the soft coolant lines to help move air bubbles through the system. Once coolant starts to spew from the vent screw, you have the air out and can replace the screw. USE EXTREME CAUTION AS THE LIQUID WILL BE VERY HOT.
6. Leave the go kart running through several cycles of the fan turning on and off.
7. Replace radiator cap. Turn engine off.
If at any point the overheating light or alarm turns on, immediately turn the kart off. Let the kart cool down and retry the process. Now you should have all of the air bubbles out of your coolant lines and be able to run your machine with confidence. If you need any assistance, contact our partners at GoKartMasters.com- the Trailmaster Technical Experts.