Degreased the engine yesterday in preparation for the Ilminster show tomorrow. Took it out to fill up with petrol this morning and had an intermittent hollow sounding clunk.
Back home, it tended to occur when I shook the engine from side to side so checking all around for something hitting something but could not find anything. Shaking the engine from underneath, it sounded as though there was something hitting the jambonneau, but could not see anything.
I think I found the answer. I put a load of oil on the volute springs and, after a bit more shaking, I think the problem is solved. There is no mention on the lube chart of oiling there but I think that, after the degreasing, the springs were binding and echoing through the jambonneaux.
More knowledge to store away.
Roger_G
Roger Grix
Chris