We put over a thousand miles on the Westy visiting Nashville & cruising Tenn
& KY. last week. I had the 4X super-zoot injector cleaner in the first tank
of gas, & used nothing but Chevron 93 octane the rest of the trip. I was
pulling a trailer w/a motorcycle (about 900 lbs. total) most of the way, so
mileage of 15-17 mpg wasn't too far out of line. In general the old girl ran
better & better as miles rolled up. However, I still have  missing & a rough
idle. The exhaust pipe is sooty black inside. I took the idle control valve
off & cleaned it out w/carb cleaner. It is "humming & buzzing" as per
Bentley. So, I ordered a new coolant temp sensor from van-cafe that arrived
today. I located the old one on the side of the thermostat housing. Before I
attempt the swap-out, am I going to loose coolant? Will I introduce the
dreaded air bubbles in the coolant? Any tricks?
Another question, Bentley describes testing the oxy sensor using a CO meter
in the tailpipe, is there a "shade tree mechanic" method I can use without
the CO meter? (I do have a Fluke digital VOM).
Thanks much for all the responses to my first Bow-wow blues post,
Ron Komoroski