QUESTION TWO: WHAT ABOUT DISTILLED WATER?
If
you want to put water in your radiator, it is best to use distilled
water. Distillation is a process that takes water and boils it. While
the impure sediments stay down at the bottom, the steam vapor is
collected. The liquid that is collected as vapor is the purest form of
water you can buy. By using distilled water, you eliminate the
impurities and hardness that scrapes, scars and corrodes the cooling
system.
QUESTION THREE: HOW HIGH SHOULD THE WATER BE?
To the top. If
the fluid level drops by even a small amount, start looking for the
leak. The most likely places are head gaskets, hoses, the radiator cap
or water pump seal.
QUESTION FOUR: WHAT DOES A RADIATOR CAP DO?
Since the
boiling point of fluid is higher when pressurized, the manufacturer
takes advantage of this by pressurizing the cooling system. The radiator
cap keeps the coolant under pressure. If you think your bike has a
cooling problem, the next step is to inspect the cap O-rings and gaskets
for cracks. A broken gasket means the cap can release hot coolant out
the overflow where it exits as steam. Even if no broken gaskets are
found, the radiator cap is still suspect. Since the cap can't be checked
until you get back to the shop, resort to a process of elimination.
QUESTION FIVE: WHERE SHOULD TROUBLE SHOOTING START?
Overheating
can be caused by a myriad of problems: a faulty impeller, coolant
blockage, lean jetting, thrashed top end, bad coolant or a blown head
gasket can all cause steam to be pumped out the radiator overflow house.
Starting
from the top, anything that impedes the speed with which the coolant
flows through the radiator will cause it to overheat. Old, contaminated
coolant can have such a low boiling point that it will spew out the
overflow when the motor is used hard.
If you
have a water pump seal leakage, a quick check of your gearbox oil will
tell you if water is leaking into the tranny. Oil with water in it looks
like milk.
Finally, a
blown head gasket can leak exhaust gases into the coolant and
pressurize the system so much it triggers the radiator cap's blow-off.
QUESTION SIX: CAN I KEEP RACING IF MY BIKE IS LOSING FLUID?
This
is a personal call. If you haven't found any obvious signs of a leak
and the bike isn't blowing steam out of the overflow hose when being
ridden, you need to judge how far the coolant level dropped in the
radiator. If you can't see any coolant in the radiator, park it and have
it fixed. If the level has dropped down to the top of the inner core
structure, you could try to race, but first, borrow a radiator cap from a
buddy, fill it up with water and have a friend signal you if it starts
steaming.
QUESTION SEVEN: HOW DO I TEST MY COOLING SYSTEM?
Snap
On sells a coolant system pressure tester. The Snap On cap replaces the
OE radiator cap. Use the Snap On hand pump to inflate the system to the
maximum pressure listed on the radiator cap. Coolant will leak from
wherever the fault is. If fluid comes out the overflow before reaching
the blow-off pressure, the radiator cap is bad. If the coolant system
holds the maximum pressure for 10 minutes you're fine. A good race shop
should have a cooling system pressure tester.