I owned an 80 which I sold after one summer and replaced with an 86. The
air cooled 70 hp boxer just doesn't cut it for any kind of sustained
driving. I bought it with a blown engine and replaced it with a good
quality rebuilt motor, and then put in a set of gauges: oil temp, cyl
head temp and oil press. We drove from San Francisco to Seattle along
the coast; even with cool ambient air temps at 55-60 mph the oil temp
got up to 300 F and just stayed there no matter what. That's way too
hot--oil breaks down rapidly at that temp. When we got back I put in an
external oil cooler with a thermostatically controlled electric fan, all
mounted above the transmission. It helped a little; the oil temp dropped
to around 250 F. But 70 hp is just not enough for something the size of
the Westy.

Last summer we put 5,000 miles on our 90 hp 86 Westy. It never got out
of the mid range on the coolant temp, and cruised at 70-75 mph all day
long even with the a/c on. It didn't burn a drop of oil and was just a
real joy to drive, especially with the power steering.

For me there's no comparison. I'd never buy another air-cooled Westy.