See now I have always thought my 900 runs quite hot and obviously as the ambient temperature goes up then cooling air is not so erm, cooling. It certainly runs a little crisper when the air cools during Summer evenings.
It's never caused a massive problem other than the dreaded vapour lock that can sometimes affect the carb'd engine- I have had this happen twice both on extremely hot days and when stuck/filtering in traffic but happy to say (touch wood) it has been fine since I replaced all the fuel lines and overhauled the vacuum tap and pump,
Conversely my Yamaha Thundercat runs pretty cool all the time, on my trip to France two weekends ago a couple of thermometers outside the Pharmacies (funny how all Pharmacies seem to have those over there) in the towns were reading 35 degrees and the bikes gauge only rose from 60 to 75 when slow moving in traffic the whole time I was there.
It might be worth noting for those of you with plumbing that I had recently flushed and changed the coolant to Silkolene Pro-Cool which may have helped.
As hot as it got:
