Frustration over hot and bothered radiator
OUT FOR A RECENT HOT Sunday jaunt with a couple of pals – both as it turned out wisely riding air-cooled machinery – the K75 boiled its rad while caught in stop-start traffic in a touristy town. After cooling off and applying much expensive bottled water, I nursed it back home and began a long, tedious investigation of the cooling system, starting with knucklescraping detachment of bodywork blighted by corroded steel fixings in alloy castings. Doing it by the workshop manual meant firstly testing the rad pressure cap, which was OK, then the seal on the thermostat valve (OK), then dangling that in a pan of boiled water to check that it opened and closed (OK), then detaching, cleaning and checking the badly corroded-in temperature sender switch to the fan (OK). Having removed the radiator before any of the above mentioned I could’ve simply tested the fan which eventually proved to be seized after many years in storage (previous owner). So time for a warranted used one from BMW spares heroes Moto-works (motorworks.co.uk) and at £75, half the cost of a new item. The moral of the tale being not to always do things by the book, especially one written by Mr Haynes.
The culprit: seized fan motor
Pressure ller cap: ok
Rad thermostat tested
Been riding for: 54 years Owns: Honda VT500 Ascot Tracker, BMW K75S, (CB400N Tracker almost sold)