Jay,

The 20B utilizes a split shaft.  You're going to have to separate it in
order to disassemble the engine.  Bob Darrah built a splitter tool from
a
threaded shaft and a 1" thick bar of steel.  The threaded shaft will
need
to
match the threads in the #1 lobe on the crank, 18mm if I recall
correctly.
Thread the shaft into the lobe, slide the 1" bar over the other end of
the
threaded shaft until it fits snug against the nose of the eccentric, put
a
nut on the threaded shaft to tighten it all down.  You may want to use a
soft aluminum or brass spacer so you don't bugger up the end of the
eccentric.  Tighten the nut until it cocks the 1" bar a little, then tap
the
other end of the bar with a hammer and it should come right apart, at
least
that's how it has worked for me twice.  Now you can finish disassembling
the
engine.  Remember the sequence for when you are ready to re-assemble it.

Mark S.


Mark--do you have a photograph of the 3-rotor eccentric separation tool
installed on the eccentric?

Steve Beckham

Steve,

Yes, see the last picture in the group.  The TR (threaded rod) screws
into
female threads in the #1 lobe (the removable one).

I should have mentioned that the picture doesn't show the BN (big nut)
that gets threaded onto the other end of the TR.  The purpose of the BN
is
to lock the BB (big bar) down against the end of the e-shaft.  I
recommend
you put a piece of softer material (like aluminum or brass) between the
BB
and the e-shaft to keep from damaging the threads.

Once it is assembled, you take a BH (big hammer) and smack the
unsupported
end of the BB.  The #1 lobe should pop right off.

Mark S.


Mark--thank you for the photo showing the tool installed on the shaft.  At
the same time it not only the construction of the tool very clearly but also
how the tool works.  Proves that indeed a picture is worth a thousand words.

Steve Beckham