Sorry I hate long posts but this will be one and I'm not sure it is relevant to a bike.
A relative inherited a car from his mother, she owned it from new and it was serviced it's entire life by the same mechanic.
The new owner drove the car from Melbourne to Sydney a trip of 900ks, on the highway the car was perfect but when he reached city traffic the engine temperature climbed, it did not overheat, it just got hot.
He asked me to look it over, I found everything as it should be and working well, I installed a over ride switch so he could turn the thermo fan on if he needed to on his trip back.
On the trip home it did the same thing, it ran fine on the highway but the temperature climbed when the car slowed down.
He took the car to it's life long mechanic and they determined it needed a motor rebuild, I called BULL SHIT but he had the motor rebuilt anyway.
After the rebuild the problem persisted, the mechanics were stumped and could give no reason for the problem but did not find a problem with the motor when it was stripped either "which they did not tell my mate".
The car sprung a exhaust leak so he took it to the local exhaust specialist, when they removed the exhaust they found the cat had been gutted, it was still there but it had no internal parts.
When they rang to tell him he needed a new cat he asked why, they told him while he was moving at speed it would be fine but when he slowed heat from the exhaust would transfer back up the exhaust and into the motor.
This explained his symptoms exactly, he had the new cat fitted and his over heating problems went away.
He returned to the original mechanic to get back the money he paid on the rebuild as they were the ones that gutted the cat in the first place, they had done it about 4 years earlier to save the old girl some cash.
After I was told this I started to investigate and found heaps of storeys where people had unexplained temperature rises after stuffing with their cats.
Some of the 19 rides in my shed
2014 V2, Snoopy
2009 Wee, Pumbaa the pig
WR450F, The Blue Postie Bike
YZ250N smoker with rego, Stinky.
Yamaha MT09 (FZ09), The Scud missile.
Club Lead not Club Med.
He with the most toys wins.
Out of my depth in a puddle.
Live life on the edge you will see more that way.
Ridding a motorcycle keeps things in balance.
At the end of each trail and at the end of each day history is made.