Replaced the temp sender - always seemed low, barely reaching the green in extended idling. Odd sized hex - 18mm.
Driving along easily (ambient ~20C) indicated low end of the green; idling in traffic for a bit it eased up nearer the middle, so happy with that.Extended idling before would barely get near the green.
The thread - 18tpi, but OD is 0.605".. neither 9/16 (.562) or 5/8 (.625). very strange. Next job is get the leaking overflow pipe in the filler neck fixed, and the rad cleaned.
Speedo - comparing to a GPS, it seems to vary somewhat...not unexpected. Sometimes reads high, sometimes low. When low its at least 10kph. Not flicking much at a steady speed, but as you coast down to a halt the swings get very bad - 0-40 sometimes. Cable needs some attention? Can I pull the inner out from the top safely?