From:Doug Miller Electronic:radarsprint -A- yahoo.com
Subject:RE: 54 165 ST 3/4 Date:Fri Aug 26 22:44:28 2011
Response to:16242
Gene

What makes you think other than a 14X1.25 plug fits your bike?

All the 165 heads I've had and looked at had 14mm plugs. Some of the bikes (As any older bike might have been altered) have been altered to other threads, 3/4" is one of the taps for plug inserts, I don't remember the manufactures name, some are 5/8" and some heads are re-taped for an 18mm plug (earlier vintage than the 48 model S or your ST) this larger plug is 18mm, not 3/4", and adapters may be available to go from 18mm to 14mm.

Doug

----- ORIGINAL MESSAGE FOLLOWS -----
Looking for correct (Large) plug fo 54 165
Have purchased part no. 32305-48 and this is
widely advertised for this model but it is 14mm
Have two #2 plugs to trade for one correct one.