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Postby piaggiocenter » Sun Oct 22, 2006 6:38 pm

Liquid cooled bike not bein' chilled? :(

Try reading this then :}:)

OK, Always remember HOW your liquid cooled bike is cooled.

Coolant (Mix of Water and Anti-Freeze/ Corrosion Inhibitor) is pumped around the engine, and cooled by a Radiator.

To keep the engine from running too COLD a thermostat is added into the system, which normally opens at 85-90 degrees. When you first start the engine, the Coolant circulates around the engine only, until it reaches normal temperature, at which point the Thermostat opens, and the Radiator prevents the engine from getting any hotter.

The radiator is cooled by Air being forced into the front of the bike by forward motion, so if you have stopped, the engine will get hotter and hotter until it boils. This is not good for the engine...

Larger engined machines have an electric cooling fan which cuts in just before the engine gets too hot.

So, a quick recap is as follows;

1/ The Water pump circulates Coolant.

2/ The coolant is cooled by the Radiator.

3/ The circulation is regulated by the Thermostat.

4/ Overheating when stationary may be prevented by a Cooling fan (When fitted)

OK so far?


Check the coolant is correct, and up to level. (Change coolant every 2 years, use ready mixed stuff)

Check the Radiator is not blocked from passing air or crap inside. (Use a garden hose to check flow)

Check the Water pump is actually pumping (Remove pipe from pump, and see how much pressure it creates by blocking the pipe with a finger)

Check the Thermostat is opening when dunked in boiling water for a minute. (The 'hole' should be unblocked by the spring loaded plug)

Only overheating when stationary or very slow moving? Check the FAN cuts in before it hits the red!

This entire procedure may require a fair bit of dismantling which is up to you, and unless you know what you're doing, DON'T bugger it all up by attempting to fix it, and be careful of being burnt by scalding hot water!

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Postby turbinator » Sun Oct 22, 2006 10:49 pm

on my yamaha aerox the standard setup had 2 pipes goin from the cylinder to the carb i quessed this was to heat the petrol befor it entered the engine is this right? we anyway on my new carb (delorto phbg) the pipes are on either side of the carb and go down into the chamber at the bottom of the carb so if i put these pipes on wont the antifreeze go straight down into the petrol then into the engine? so are these pipes for a different purpose?
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Postby GTi Driver » Mon Oct 23, 2006 9:54 am

Nice little explaination of it all, I'd also advise to *back flush the system* when changing the fluid to remove any crud stuck in there :D

*back flush the system* - work out the usual direction of water flow and run a garden hose into the outlet of the radiator until the water coming out is clean, then repeat the procedure with the cylinder head :}:)
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Postby monty9120 » Mon Oct 23, 2006 10:52 am

when i had my runner. it never got hot when in motion only when it was in traffic then the fan kicked in and the tempreture lowered abit
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Postby samjac68 » Sat Dec 09, 2006 11:44 pm

im also wondering about this lol, i drained all the coolant out of my aerox as i decided to take the motor out for a clean up.

ive done gnvq motor vehicle mechanics so i can relate a lot of stuff really, ive got a bottle of antifreeze and im wondering what ratio to mix it, most people say 50:50 for cars, i was told this is unnecessary and 40:60 shouldnt freeze or cause corrosion but will cool the motor better (for a car)

can anyone tell me the right mix ratio for coolant:water, also if anyone knows where the thermostat is on an aerox 50 id apprechiate it lol

cheerz all
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Postby bunter » Sun Dec 10, 2006 3:48 pm

Go for a 50/50 mix of antifreeze and distilled water.
you can buy antifreeze thats already mixed. :}:)
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Postby cbbigboy » Wed Dec 27, 2006 9:49 pm

Coolant quality checkers are easy to get hold off, always handy to keep about, some are just like a tiny pipette with balls that float or sink

the more that sink the better

but it will have a manual to explain cooling levels etc
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Postby MALOSSI » Thu Dec 28, 2006 3:17 am

cbbigboy wrote:Coolant quality checkers are easy to get hold off, always handy to keep about, some are just like a tiny pipette with balls that float or sink

the more that sink the better

but it will have a manual to explain cooling levels etc

Hydrometer 8) :P :D :bike:
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Postby boatmad » Sat Oct 11, 2008 9:28 am

One more point of note. Most water pumps are driven directly by the engine, often off the camshaft, If the water seal fails it is possible for the coolant to get into the engine. The sympton to look out for is the lube oil turning white and lumpy like sour milk. If you see this dont run the engine until you fix the pump as the oil is useless and the motor will seize.
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Postby piaggiocenter » Sat Oct 11, 2008 11:07 am

Not the case on any Scooter I can think of though!

Two strokes are unaffected of course, as the oil is injected into the inlet tract, and most four strokes pumps are crank driven, seperately from the crankcase or sum area.

Nice thought though.... :D
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Postby nickhod » Thu Jul 23, 2009 9:44 pm

My Runner VXR 200 tends to blow out coolant from the resovoir cap its more than just a fine spray I have changed the cap but still the same. wondering if it could be the head gasket? but theres no water in the oil or vice versa.Any sugestions?
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