Well just to refresh this thread after 2 years. Decided to replace the CHT as I am replacing the reference and speed sensors. Thought about it for a few days " What about if I cut the wires and then cannot get the CHT sensor out?". Well that is just about what happened!! Should have trusted my instincts!! Cut the wire and then tried to back out the sensor, well after 26years you can imagine it was not going to be a ' piece of cake". Eventually it started to move but after a few turns it got stiffer, so WD-40'd it tightened it back in a bit and then backed it out, after it was out 5mm, it just kept spinning and would not go in or out!!. A few choice words like 'golly gosh!!' and ;'Oh bother' were heard. I managed to get a broad screwdriver around the back and into the gap between the Head and the CHT and as I started backing out the CHT a bit more I turned the screwdriver in the gap to help force the CHT out. It worked, although the threads on the CHT are stripped I think the threads in the head are OK but just need to be tapped to clean them out
. It could have been worse!! Does anyone know what the thread specs are on this hole for the die size. Thanks all.