For those that are interested
here is the story so far. Engine removed from Acrowot and put on test bed. Virtually nothing, a few seconds of combustion and nought else.
Right, exchange glow plug for new OS F type. Remove carb and mainjet and blow out with compressed air.
Hello! what's this? Carb bracket on crankcase casing broken.
Manifold gasket a bit compressed and wet therefore suspect possible air leak.
Check valves at same time. Nope! Some tw*t has broken one of the screw heads off. This is a LOST cause. As it happens I have a similar engine which Lee saw running earlier. Sold!
I have fitted it to the Acrowot but the throttle linkage will need moving back to where it previously was located. While the engine is off, might as well cover all bases and pull out tank. Oh dear! Tank bung perished, clunk touches back of tank, lines a bit soggy too. The tank also had two exhaust lines hence the drain line did not drain... Engine mounting bolts - two too long and hitting tank.
Bung and lines replaced, (coloured one for carb line) all plumbing replaced and new ally pipe for carb line (the other one was corroded. All I have to do now is make up a new linkage using the snake I moved earlier. Lee, I have re-secured the battery for easier access whilst I was at it.
Mixture screw is now accessible from top - much safer.