Causes
Internally rusted petrol tanks are not only a problem of classic motorcycles and cars. Unleaded petrol is aggressive and corrodes the tank from the inside.
The problem appeared with the disappearance of leaded gasoline
In 1988
environmental reasons lead to the replacement of leaded fuel with MTBE
(methyl
tertiary-butyl ether). Unfortunately the new environmentally friendly
fuel
caused new problems in fuel tanks.
Because MTBE is
hygroscopic*, water is now accumulated in petrol tanks, causing slow
corrosion. (* The
ability to retain moisture from the atmosphere)
Since the late 90s
MTBE was replaced by even cheaper chemicals like methanol or ethanol.
These
alcohols however, absorb even more water and that leads to even faster
corrosion.
Other causes of rust
• Clogged overflow pipe
• Vehicles left standing for long
periods
Rust particles cause serious damage
The effects are:
• Blocked carburettor jets
• Low-pressure petrol valve
malfunction
• impaired function of the float needle valves