Back flush secondary and primary systems
Clean filter in primary
Add Fernox descale to primary, run hot and flush
Five water changes in primary
Lower temperature indication
A lot of muck removed
New issue gulp
Engine overheated on run up to Texel due my bad connection of cable to circulation pump. Cable pulled out of double secured choc block. Think I caught it in time, most but not all coolant boiled off. Not good but engine started and ran fine. Now a new issue, during engine runs to flush out system engine decided to hesitate and run down fairly quickly; did not want to start. Diagnosis fuel starvation so change fuel filter and bleed. I have known a few small boat diesels and it does seem you need to bleed them quite a bit, more than you think. However I am not seeing good starting, perhaps a little better after last bleeding. I’ll run the engine for a good period. Maybe an hour and see what occurs. Ghosts in the machine? Plan to inspect inside of exhaust, see if water channel is blocked with residue etc. That might also restrict secondary water flow and add to thermal overload. Hmmm, it is a bit Zen living with these conundrums but, I think, it does offer a kind of pelmanism.