Jon began work on our 1956 Jensen 541, currently undergoing a recommission at the Bridge Classic Cars HQ in Suffolk, by stripping and freeing the carburettor piston, ensuring the lifting pin raised it smoothly and that it fell back to the bridge correctly. He weakened the mixture, reducing the jet depth from 2.65 mm to 1.3 mm, leaving ample scope for further tuning. The float bowl was emptied and cleaned out before being blown through and rebuilt. Jon repeated the same procedure for the other two carburettors.
He disconnected the fuel pipe and used the pump to empty the tank, noting the pump was weak. While the tank was draining, he removed the spark plugs, then refitted them once the work was complete. The oil and water levels were checked and found satisfactory. Around 25 litres of old fuel were pumped out, and 10 litres of fresh E5 fuel were added.
After starting the engine and moving the car outside, Jon found it would not continue running, so he parked it outside the Classic Lounge for Nick to take photographs. He then carried out a tune-up, enriching each carburettor by half a turn on the jet adjuster before retrying. The engine was then able to sit ticking over, allowing him to adjust the idle speed. Once warmed up, he carried out a road test, finding it drove acceptably for its condition. On returning to the workshop, he made a final adjustment to the idle.
