I'm a formerly certified tech who changed careers in 1997. The easiest way to change a K bike sight glass:
From my experience, I would suggest a very light coating of clear sealer, (same stuff used for timing covers) and waiting 24 hours for the sealant to sealant to cure BEFORE putting in the new oil.
Using the technique of sealing and not putting any fluids in until the next day, was one of the best decisions I ever made as a tech. It virtually eliminated comebacks for oil/water pumps and timing covers.
Try it, you might like it.
Andy Newell
All contents Copyright © 1995 - 2009 Internet BMW Riders & the original author(s)
K-Bike Tech Pages
Maintainer: Tom Coradeschi WWW - email
Last Update: 05 October 2007