At last, the engine is rebuilt; everything is in place and working correctly and both cylinders are firing in harmony. But she refuse to rev beyond tickover and she is still leaking smoke and fumes from the engine block. What could we have omitted to check? We pondered over this question for a few minutes before Stuart casually placed his hand over the exhaust and pointed out that there was hardly any pressure from the pipe. He then placed his hand on the air filter inlet and discovered that the air was blowing back. Eureka! The exhaust is blocked at the silencer and the engine is choked up. It must have been caused by me running the engine when it was labouring on one cylinder, ironically I was running it, often at high revs, to try to burn off what I assumed to be a build-up of coke. In effect I was compounding the problem.
Stuart, Alun and I made several attempts to clear the blockage – blasting it with air, flushing it with water, hitting it with a hammer – but none were successful. A new silencer was the only solution. Two days later the new box was installed. Thanks guys!
And that’s it. Approximately 18 months later (work was intermittent), due to the efforts of numerous helpful enthusiasts, the engine runs beautifully again. Finally, I can go cruising. Happy days! Next task: repaint the exterior.