Hi nelsonstansbury
Doesn't seem bizarre to me.
I assume You let the engine run from time to time for a short periode ( some minutes) ?
If You burn gasoline in an engine, You got water, Co2, some aromatic polycyclic hydrocarbon and sulphur as exhaust.
If the engine (and exhaust pipe) is cold, this mixture is condensing inside. Together with sulphur You got an agressive sulphur acid (H2SO4) which let rust every exhaust-pipe from inside, even those made of stainless steel (although stainless steel resists very much longer) ! :shock:
The only way to avoid such problems is always to let the engine run until the exhaust pipe is really hot till the end, so water and acid inside can evaporate completely.
If You start the engine only for some minutes or You go on short shopping-tours the exhaust pipe oxidize much quicker than if You take the bike on long tours !
Another drawback is that You got these exhaust-gas not only in the exhaust-pipe, also a small amount is bypassing the piston and accumulating in the engine oil! There You got the same problems (acid) after some time as with Your exhaust-pipe.
:arrow: Always avoid short distances, especially if You try to conserve Your bike. On the contrary: long tours and moderate revs will conserve !
Or You put the spark plugs out, put some motor-oil in and turn the back-wheel by hand from time to time (2nd gear) or kick (if kickstarter is existing) if You have the bike staying in a storage or so