i think the radiator has a faulty divider plate in the lh tank. it's a pretty grungy looking rad with flattened fins on the front by the brake hoses, but it used to be fine. when i was flushing it out to see if it flowed water and where, a couple of things came out of it that took me a bit by surprise, and later, after the below bit, it occurred to me they were bits of thermostat. i'll take a photo of them tomorrow.
i had a new radiator - a 91 that's a touch different to my 89, and a matching fan. i was quite torn by the thought of fitting a new rad to it, but in the end tried it out and, while it's not overheating and spewing out coolant, it's still running hot, to the point of fan on while riding along.
so there's definitely something else up, and i think it's the thermostat. well, i hope it is. i just wanted this thing to be an easy back on the orader, and it's pissing me off. one of my 907 customers cut up an aprilia thermostat and used the insides with the original 907/851 top housing to fix his.
or i could get some 916 lower hoses and water pump cover and go that style of hoses. obviously, the thermostat replacement is easiest.
