Motorcycle Repair: temperature gauge readout, coolant level, temperature gauge

Question
when my bike is at idle speed i have a readout that continues to climb temp but when i go down the road the readout goes back to blanks while i am accelerating why does it do it and how can i fix the problem

Answer
Hi Chris.

Since you didn't tell me anything about the bike beyond the overheating, I have to give you the info on both air/oil-cooled bikes and liquid-cooled bikes.

Sitting at idle, the bike has no air flowing over it, so the heat does not shed as easily.  When you are moving, it sheds the heat because the air is moving over the heat exchanging parts of the engine.  Adding an oil cooler can help with this issue, but the bike still needs to be moving for this to be effective.
 Even so, the bike should not be overheating as you are describing, unless you are spending huge amounts of time at idle, not moving.

That is for an air-cooled bike.  For a liquid-cooled bike, it is similar, but just a bit different.

There are 2 heat exchanging elements to most liquid cooled bikes.

1) The engine may have short fins to help with heat exchange or it may have an oil cooler.  It may have both.

2) The bike will have a radiator, just like a car.  If there isn't enough air to keep the coolant temp down then the bike will tend to overheat.

Overheating of a liquid-cooled bike will occur when there is not enough coolant in the system or if the cooling fan is not working. Check your coolant level if you have a liquid-cooled bike

If the fan is not working it could be because the fan motor is broken or the thermosensor has failed.
 Jumping the thermosensor leads with power on will tell you if it is the fan motor or the thermosensor.

If none of the above solutions work for you, then get the bike into a shop for proper assessment and repair.

Good luck and ride safe.
FALCON