Interesting Phenom

Totally not normal - to have good weather in December. Stop bragging it' bloomin freezing here not to mention wet

 

The clue is ‘last night’ and, yes, it is totally normal for headers to glow in low light if they have not been exposed to any airflow.
Just remember the oil cooler is also taking your primary coolant (the oil) at much the same temperature from the cylinder head area without the benefit of any air flow. This in turn raises your sump temperature and exposes the weakest link - the plastic oil pump gear - to excessive heat. Prolonged idling is a bad idea!
Suffice to say cylinder head temps are also an argument for fully synthetic oil in these bikes as synthetic oil breaks down less readily at extreme temperatures.

 

What site is this - do I know you ?

 

The JASO spec in your handbook tells you but this is the North American version of what Triump recommends in the UK......
https://www.castrol.com/en_us/unite...l/4-stroke-engine-oil/power-rs-racing-4t.html
A lot of marketing hype and subtle re-branding! Castrol is the lube arm of BP/Amoco as Mobil is to Exxon. Mobil1 Racing 4T 20/40 is much the same.

 

I have something like this for my ‘11 thruxton, as long as you have frame tubes running under the engine it works great. You can put a couple of bits of wood under the bike just to lift the oil filter clear if you need to. Or one of these to keep it upright for oil level checks etc