Bunn Crankcase Breather Kits
Visit Rex Bunn's Blog
The Bunn Breather
Kit
(BBK)… Cuts Oil Leaks AND Reduces Engine Wear, as it Flushes Toxic Blowby from
your Crankcase & Rockerbox. It is warranted in use for two years with unlimited
mileage.
The new Kit cuts oil leaks by restoring original crankcase air pressure, back to
the levels classic designers planned. Over the decades, the OEM breathers
malfunction and air pressure increases. Oil leaks are often the first sign. The
Kit suits all the usual four-stroke makes, whether singles, twins or
multi-cylinder engines, i.e. AJS, Ariel, BSA, Harley Davidson, Indian,
Matchless, Norton, Sunbeam, Triumph, Velocette, Vincent. The BBK Kit also cuts
engine wear by flushing filtered, fresh air through your crankcase. This
controlled airflow forces out corrosive blowby gases that otherwise cause this
damage to your engine, each time we start up:- * Contaminates and dilutes oil *
Washes oil film off engine internals * Rusts ferrous components and bearings *
Sludge forms * Pressurized crankcase causes oil leaks * Rubber deteriorates *
Crankcase becomes a fire hazard.
The BBK Kit includes- valves, air
filter, tubing, cable ties/clip, spare seal and comprehensive instructions. It's
a simple, easy-to-install solution for classic engine oil leaks, crankcase
pressure problems and blowby wear and corrosion. It can be fitted to nearly any
four-stroke engine, to improve engine operation. It involves no permanent or
unsightly changes to your engine. Flowing fresh, filtered air through the hot,
closed-off rockerboxes and crankcase helps oil return and the engine to run
cooler. It also helps prevent any dirt being sucked into the engine via existing
oil leaks. Engine power may be enhanced on some bikes, as crankcase air
pressure, downforce work-loads and drag reduce. Research shows oil leaks are
signs of more serious problems. Noted Classic engineer and Norton racer Peter
Williams says, in his June 2005 Classic Bike review of engine
breathing..."...leaked blow-by gas is nasty, obnoxious, and corrosive stuff and
it is best to have as little as possible in the crankcase..." Blowby occurs
every time we ride. It forms a corrosive, flammable mixture, that eats away at
our engines, if left inside. Blowby is ~70% fuel, water, sulphur dioxide,
nitrogen oxides, soot and ash. It's like a concentrated acid rain. The BBK Kit
is an effective conservation aid, designed to keep classic motorcycles on the
road into their second century.
Disclaimer: As user installation and operation vary widely, this kit is not
guaranteed to work on every make and model of classic motorcycle; for instance,
some J.A.P. engines.
635-01 Classic Universal Kit
Instructions for 635-01
635-01Royal Enfield Classic Kit
Instructions for 635-02