The drain plug is on the frame, just behind the front wheel.
Not sure of the size but here are the Yamaha part numbers 3VD-13455-00-00 Plug 214-11198-01-00 Gasket Hope This Helps.
0.031 to 0.035"
The oil drain plug for a GSXR 600 is on the bottom of the motor, usually near the rear of the bike. You will need to remove the fairing to get to it, and it will be the largest "bolt" on the bottom of the bike.
part #: NGKDPR8EA-9
.028-.030
http://www.bossturbo.com/cbr/howto_oilchange.shtml
.030-.040
NGK D8EA/DR8EA/DR8EIX or equivalents.
The spark plug gap in a Yamaha Seca is 1/2. It can be easily obtained and is very affordable and likely to be replaced by the owner. It is a quick replacement.
10.8 oz. per leg
The proper spark plug gap for a 1997 Yamaha YZF600 should be .028 inches. The best spark plugs to use in a YZF600 are copper.
17 mm.