M2CW:  I have a Solex carb (on a 91) so there is no ECU
to compensate for other changes.  When I put in the
Bosh plugs (these are single tip, but the super-plug
platinum none-the-less) the RPMs at idle increased about
500 rpm.   For the record,  the old plugs were not bad
and were relatively new.  I had to  turn the carb setting
back down to get the idles back to 900-1,000 rpm.
m2cw.  malcolm