blue smoke under compression braking.

[Fuzzzydog]

Hello again, just throwing this out there for (hopefully) BTDT's

88 5ktq with an MC engine. car has almost 300,000 kms and no idea how many
kms on the engine (this is at least the 3rd car it has been in)

Starting last year I began to notice blue smoke behind the car after
compression braking down a hill - ie coasting down in gear but totally off
the gas. Don't notice any smoke while I'm going down, but when I give it gas
at the bottom it puffs very blue.  This has drastically increased now and
also I can smell the oily smoke when going down a hill if the sunroof or
windows are open.

I am thinking valve seals, but it has been suggested to me that it might be
rings.  I will be doing compression and leakdown tests this weekend and take
it from there but always interested in hearing from the collective....