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Engine coolant & overheating.

Posted: Thu Jul 24, 2008 4:39 am
by masterofinsanity
Coolant is used to prevent an internal combustion engine from overheating. It serves to maintain a steady temperature inside the engine through the thermostat. Engine performance is highly dependent on the effectiveness of the cooling system.

A couple of factors can make the coolant and engine overheat (such as fuel delivery problems, ignition failures or engine oil leaks) and cause some serious damage. Cylinder head deformation, head gasket breaks and piston jamming are some examples.

The fuel delivery system must be in good condition -- leakproof, airtight and clean (no dirty residues). Otherwise, the air-fuel mixture deteriorates (too much air, not enough fuel). This situation can lead to a temperature increase inside the combustion chamber and of the cooling fluid.

The ignition system can also induce engine overheating: beware of non-complying spark plug models or those that do not match the right operating temperature range (please refer to the websites of spark plug manufacturers like NGK, Champion and others). Improper pre-ignition settings are another potential cause for overheating. To make sure your motorcycle has the right settings, go to your local mechanics specialist.

Furthermore, engine oil levels should always be monitored to prevent the engine from overheating. Use your own eyes or the oil gauge: a low oil level will result in insufficient lubrication, increased friction and heat as well as premature wear. A non-recommended oil grade might also lead to overheating.

Likewise, low-quality oil designed for cars won't meet the requirements of a motorcycle engine. This type of oil does not contain the necessary additives to withstand the kind of engine speed a motorcycle usually achieves (10,000+ RPM).

Make sure that your oil grade is recommended for your bike follow the instructions and recommendations in your owner's manual.

Oil must circulate at a certain speed and freshen up in the pan to ensure constant lubrication of the internal parts and maintain a steady temperature. That's where the cooling system comes in, maintaining ideal temperature to allow optimum engine output.

Now that you know the proper engine parameters, you got to make sure to have the correct blend of water and antifreeze. Both H & L models use a 50/50 coolant mix ie 50% antifreeze to water.

Be careful when choosing the coolant for your motorcycle: it has to meet the standards of your manufacturer; otherwise, it could damage the whole cooling system.

This is what your coolant should NOT look like.

Re: Engine coolant & overheating.

Posted: Fri Jan 30, 2009 8:58 am
by masterofinsanity
This is what happens when you don't have sufficient antifreeze in your coolant mixture.

Photos courtesy of diesel.

This is why its important to look after ur bikes guys!

Posted: Mon Aug 03, 2009 11:50 pm
by saka_ZXR
Right well after flushing my rad on my zxr the other week to fix an overheating problem i figured id do the same with my KLR as i doubt the guy before me would have done it and it cant hurt to flush it every now n again :)

Well i couldnt fucking beleive what i saw when i drained it! I doubt it'd ever been drained since it rolled out of the factory in 1991!

This is the result:



As soon as i saw what had come out i knew i had to completely flush the whole cooling system! There must have been 18 years worth of toad, rust and f*** knows what in it cuz this is what the filter looked like:



I must have spent about 2 hours completely flushing everything and making sure i got rid of every last bit of toad from the cooling system.

Gonna keep my eye on it and hopefully it should be sorted now :)

Now i wonder how many of u are gonna go check ur rads now :p