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There’s a reason why your engine is overheating, and depending on the cause, it could be an easy fix – or not.

Tune in to discover:

  • 7 common causes for an overheating engine – whether it’s liquid-cooled or air-cooled 
  • What to do about it


Hello, and welcome to another episode of 30-minute motorcycling – a podcast for those riders who are at the beginning of their own Dual Wheel Journey, where you’ll discover something new about how your motorcycle, moped, or scooter works – in less than 30 minutes.


Is your engine running a bit too hot? Like, hotter than usual?


Well, you have an overheating problem. 


But why does this happen – and more importantly, what can you do about it?


That’s what this episode is about – we’re going to talk about some common ways you can stop an overheating problem – whether you’ve got an air-cooled or a liquid-cooled engine.


If you need to know the differences between air-cooled and liquid-cooled engines, episode 25 of 30 Minute Motorcycling goes into more detail about it.


Otherwise, let’s get started. Since most modern motorcycle engines are liquid-cooled, let’s start there.


As a brief reminder, a liquid-cooled engine relies on a mixture of water and glycol known as “coolant” to – well, cool down the engine.


Of course, that’s assuming that there’s enough coolant in the cooling system. Therefore, check your coolant level, and if it’s looking a bit low, top it up, and you’re good to go. Easy as 1-2-3!


Unless of course, you happen to see a puddle underneath your motorcycle or scooter, and you’re positive it’s not engine oil or water condensation. 


In that case, you’ve got a coolant leak somewhere – probably caused by a crack in one of the cooling hoses. 


But even if these hoses are in tip-top shape, if an end for one of those hoses isn’t attached properly. It might even be possible that the leak is coming straight from the radiator.


Either way, check the coolant hoses and radiator for leaks and repair or reattach the ends of the hose if needed.


The next common reason why a liquid-cooled engine is overheating is a clogged coolant passage. This is similar to a coolant leak – only, in this case, the problem isn’t that the coolant is spilling out, it’s that it’s not going anywhere at all. 


To solve this problem, flush out the entire coolant system and refill it with fresh coolant.


And the last common reason for an overheating liquid-cooled engine is a broken water pump. Since this part is responsible for pumping the coolant around, if the water pump doesn’t work, the coolant won’t go anywhere – and you guessed it, it won’t cool down the engine.


If you have a broken water pump, the best solution is to remove it, inspect it, and if needed, replace the water pump.


So those are some of the most common reasons why a liquid-cooled engine might overheat. 


If air-cooled engines didn’t overheat, we could stop right here – but that’s simply not the case.


An air-cooled engine might not need a water pump, let alone any coolant, but it can still overheat, such as if the cooling vents are blocked.


Remember – this is where the air needed to cool down the engine has to go through. If they get clogged up, no air can enter the engine, and therefore, the engine won’t cool down.


To solve this problem, try cleaning the vents out, and adjusting the engine cowling if you need it.


And before you look that up, an engine cowling is the removable metal cover part of the engine.


Also, do you have an air-cooled engine with a fan? Then you should know that if that fan stops working, the same thing happens as if the cooling vents get blocked – i.e. no cooling of the engine.


So if you’re not sure if your fan is working, check the fuse controlling it. If the fuse is broken, simply replace it, and the fan should work again.


If, on the other hand, the fuse IS working, but the fan isn’t, the problem lies with the fan motor – something which requires you to replace the entire cooling fan.


And those are some reasons why a liquid-cooled and an air-cooled engine might overheat, and what you can do to solve the problem. 


If you’d like to know more about solutions to engine overheating, I’ve left a link in the podcast description to a blog post on the Dual Wheel Journey about it.


Until next time, keep your helmet on and your eyes on the road. Bye!