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GAS TANK RE-FURBISHING
PREFACE
We would like to give you a background of the doers (us) and the doee (the scoot). This will help
explain what we did and what we did not do.
Doers : Two males in their early fifties with engineering backgrounds who would like to think their
refrigerator lights are operational most of the time.
Doee: A 1984 Honda 700SC Nighthawk in above average condition. The bike was purchased from
a young gentleman living in Lake Orion, Michigan. The bike had less than 10,000 miles on the
odometer when Bill (owner/doer) purchased it. It appeared to have been garaged most of its life. It
is obvious that the bike did not spend a lot of time on the road (633 miles/year, less than 2 miles/
day).
Once in its new home in North Carolina the scoot was given a general servicing:
Oil/Filter
Spark Plugs
Brake fluid replacement
Clutch fluid replacement
Drive shaft lube replacement
Lots of Armor All
Carburetor and tank petcock sediment bowl drained.
The bike started and ran great. Numerous short rides revealed a sound and reliable ride. The trips
got longer, in the 40 to 50 mile range with continuing reliability.
As a few hundred miles got added to the odometer, strange flat spots in the acceleration started to
show up. Under full throttle, the bike would go limp at about 3000, and suddenly (!) come alive at
4000. Above 7000 it ran like a scalded dog. Additionally, when started cold, the number three cylin-
der didnt want to fire.
Suspecting the carburetor might have foreign glob infestation, Valvoline Fuel System Treatment was
added to the gas tank. This stuff was highly recommended by the counter guy at Advance Auto as
being really good. It is so good that it has a special registration with the state of New Jersey for
trade secrets. Initially, no difference was noted. On the second tank of gas with the treatment, the
bike started to idle at about 2500 RPM when warmed up.
The carburetor drains indicated real problems. One carburetor flowed freely, one dripped, and two
would produce no (as in none) gas droplet. The tank sediment bowl really told the story. It had
plenty of what appeared to be powered rust. That really good Valvoline treatment was attacking
the rust in the tank and freeing it to play with the carburetors.
A visual inspection of the tank had always troubled us, but the rust seemed to be very flat and solidly
attached to the tank surface. Based on these new findings, the bike was parked and the tank re-
moved. It was time for some serious chemistry. Enter Sudco and their product RUSTOL.