Fan

[darrsi]

Ok thanks gents also Imput a new rad on and drained and flushed the whole system.
Filled it from the top end but the overflow resevoir remained empty, do i just top up from that end or do I have a blockage?

Did you use Radflush to clean the system?
It's all the waterways that get bunged up over time, and Radflush works similar to descaling a kettle.


You can top up the overflow bottle, but only do it when everything has cooled down.


Once the system is all good the coolant will rarely need to be topped up again unless the bike is in extreme heat.


When the system eventually gets clogged up over time, the waterways narrow and you'll get more fluid in the expansion tank which will eventually boil over then get released onto the floor via the overflow pipe.
Then when the bike cools down it sucks what is in the expansion tank back into the main system.


So it's a good pointer that your coolant system is healthy if the coolant sits back in the same place in the expansion tank when the bike cools down.
If it is low, or empty, you need to do the Radflush treatment.