Few motorcycle exhaust systems have
O2 sensor mounts in the header. Not many riders of custom cruisers
would be willing to have holes drilled into their exhaust system and O2
bungs welded in because this does nothing for most expensive chrome pipes.
Equally notable is that most commercially available tail pipe
mount probe designs are ill-prepared for
use on V-twin motorcycle exhaust because of the large amount of fresh air
pulled back into the system.
A more suitable home grown probe was needed that is
inexpensive, prevents the fresh air from getting to the WBO2 sensor, can
be used on a variety of exhaust systems and is easy to fabricate. An
effective design consisting of some 1.5" OD exhaust tubing, 2 washers, a couple of
compression fittings, some copper tuning and other miscellaneous parts
lying around most garages. The resulting probe proved to be very
Stainless steel hose clamps and some angle brackets
are used to hold the probe in place.