Quote:
Originally Posted by FvnnyL3tt3r1ng
Ok, so far we have this:
New coolant after flush
New thermostat
New radiator cap
Bike still overheats, I watched as the coolant spilled out the overflow hose onto the ground so the gauge is reading accurately..........
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http://www.harborfreight.com/infrare...ter-93984.html
http://faq.ninja250.org/images/2/28/841135.jpg
Your engine is coming close to seizure when it loses power.
After the coolant starts boiling inside, steam pockets that develop close to the cylinder head are formidable insulators.
The walls of the cylinder get deformed due to excessive-unequally distributed temperature (think of fire heating dry metal) and the pistons grow faster than the steel cylinder, chocking the rings and the pistons and squeezing the oil film that should be in-between them.
Avoid over-heating at all cost.
Spray water across the radiator when over-hot again.
If your radiator cannot reduce the coolant temperature at least 10 degrees (measured inlet temp - measured outlet temperature > 10), there is no enough cooling happening.
These systems are really short, in terms of performance's safety factor.
While doing 75 mph, you need to release to the atmosphere as much heat as the internal combustion is generating, which according to the link is close to 56K BTU per each hour (or 15 BTU per second) of riding.
That amount of heat is able to increase the temperature of 1.5 pounds of water 10 F in one second, which is pretty intense for that marginally sized radiator to radiate out.
Now, that little radiator is greatly helped by the speed of the cooling air.
It becomes very ineffective when that speed is reduced to almost zero; so much that it needs that fan even when the heat is generated is much lower (engine close to/at idle).
Spraying a mist of water on the radiator increases the rate of heat transfer several times; hence, it is a way to verify if that diminished rate is or not the problem that leads to overheating.