Just think, a few weeks ago there was rain so much. Even out on the hottest locations in Thailand, it was so wet that nobody really was troubled by the idea of the temperature of the engine. But, just think like this, when you're hot, so is your motorcycle. With temperatures in Thailand soon well over 32c degree, we have need to start thinking how to keep our engines cool.
There are a number of different coolants and coolant additives that make big claims about keeping your motorcycle engine cooler. The only good 'cooler' experience we have with coolants that actual cool better are waterless coolants. Most of this waterless coolants have a boiling temperature that is crazy high, so your motorcycle won steam unless it's about to melt. The only hitch is that it contains no water and won mix with water, also it's not a good thing to mix different waterless coolants, so you have to drain every drop from your cooling system beforehand.
Another point to look for to keep our motorcycle engines cooler is the radiator cap. Your radiator cap isn't just a lid. It's a valve, designed to open at a certain pressure and allow coolant to blow out before your radiator starts looking like a balloon. But manufacturers are by nature conservative, and your radiator can take a bit more pressure before it starts to distort. If your motorcycle came with a 1.1 stamped on the radiator cap (which stands for 1.1kg/cm2) you can probably replace it with a 1.3 or 1.4 without worrying about any ill effects. That might just get you out of the bottleneck before your motorcycle engine starts to boil. One of the biggest sources of heat in a modern motorcycle engine is the clutch. In fact, we've seen clutch covers reach temperatures approaching that of exhaust pipe headers. Most of the heat is caused by clutch abuse. Beyond that, slightly worn plates can make a big difference, even if you can't detect slippage. In fact, all clutches are designed to slip slightly in order to protect the gearbox from hard hits. A fresh clutch will do wonders for a chronically hot motorcycle engine.
It's politically incorrect to say this, but many quiet mufflers and environmentally better exhaust systems can cause a engine to retain heat. On the other hand, a muffler with blown-out packing transfers heat directly to the canister, and that can cause melted fairing or other plastic parts and a serious cause of other heat-related problems. As always, us your head when you decide with exhaust system to use for your motorcycle.
A source of extra heat comes with the wrong fuel, for all you know, turpentine could be coming out of the pump at your local petrol station. If your motorcycle is detonating, it's creating heat and probably damaging the engine. Good quality fuel, from a respectable petrol company, might be more expensive that the many no-name petrol stations, but it almost always pays off in cooler operating temperatures and healthier engines and happier mechanics.