hi there cope , right after looking at the impeller as you said , the impeller has the slightest bit of movement ever ( maybe 1-2mm )
after re-filling the rad ( and squeezing the pipes to check for air , although i doubt very much if it possible to get an airlock within the system !
started the bike, but unusually took two or three kicks to start ? on the first and second there was HORRIBLE grinding / rattley noise like ends were shot !
started it anyway and the knock / rattle was not there, the fan cut in after just 2 mins and stayed on !!! let the bike run regardless , ( because it was not actually hot ! ) after 7-8 mins the bike was still not "hot" to touch . . . .the head was warm but not "hot" as you would expect . . . . . .took the thermostat out of a mates gasser that i'd been riding today and knew worked 110% put it in my bike and guess what . . . . the fan was not on when first started the , after around 5-6 minutes the the fan cut in and then cut after a few seconds !!! just how it always used to !!
sweet as !! new thermostat on order , 9am tomorrow !
couldnt find any posts on here where the thermostat stays on permanently when its given up ?
now to sort the funny knocking / rattle noise that is most prominent when u kick it without HT cap on . . . . .. ??? any ideas
as always any suggestions greatly appreciated
many thanks, kenward