After its behaviour in France/Germany a couple of months ago, I've got the Sport's engine on the bench. Stripping everything down to get the engine out of the frame I realised that a 40-year old bike is probably feeling a bit weary: the fusebox had fractured completely into two halves; one airbox to carb rubber and one carb to manifold rubber tore in half when I started to remove them carefully etc. Anyway, heads and barrels off and pistons removed. The bores look tidy, with some slight vertical scoring and criss-cross honing marks still visible, although I didn't think that Gilardoni barrels would be honed...
And here are the pistons: the rear one (closest to the camera/telephone) is oily and carbony, the front one looks better. But the combustion depressions don't look like Morini pistons that I've seen before, they don't have vertical slits in the skirts and the diameter is 65.85mm. Both cylinders had 100psi compression when I checked before stripping. Any thoughts?
