Help on Lyc. 225 (R-680)

I need to converse with someone familiar with this engine. Having a
problem that is perplexing several of us. I get a normal 50 rpm drop
on the right mag, but get a 200 rpm drop on left. Have replaced left
distributor cap, rotor, high tension lead, checked all wires and
plugs....nothing helps. Replaced mag with overhauled unit...still no
luck....yet I can switch the high tension leads on the mag and the
left will run fine and the problem moves to the right. If I start it
and run it on the left mag only for a few seconds only....no.8
cylinder does not get hot at all, and no. 2 gets barely warm. If it
is a mechancial problem with either or both of those cylinders, why is
it only showing on the left mag position? We are getting ready to
check the compression to see if we are losing any...especially on
those two cyl. I flew the airplane a month ago and it was running
fine...then it sat in the hangar for about three weeks and this
problem appeared. This is driving me nuts and getting expensive.
About a grand so far on the o/h mag and dist. parts.

Thanks to anyone who can help

Jeff Foley