Increased my tool kit on several occasions when going over a vehicle I have acquired, especially in the engine bay or under the rear seat.
How about headlight frame lower mounting screw, specified as M6x12, it could have fallen out and sat in the fairings/on the block to be found another day
All the headlight frame screws on mine had a dished hex head........but that's not to say they or the OP's ones haven't ever been changed.
Thanks to everyone for the suggestions. I rode it for a few hundred miles before the world changed and nothing untoward happened. I never found anywhere to put it so I will keep it in my spares pot. The rattle returned once when hot, otherwise no problem. I'm going to - when appropriate - just ride and not worry, until the big bang perhaps...
can't remember if you did a video to capture sound? - don't rule out piston slap, symptoms fit. Another thought, you didn't take the barrel off did you?
Hi Chris. I didn't do a recording of the sound. When we're let out again maybe I should. The symptoms appear when the engine is hot so I'm not sure if piston slap would occure then? When I had the head off, at BDC the bore looked fine but didn't lift the barrel to look at the skirt. I have a new gasket set so maybe I could take a look sometime
.. Depending how many miles has engine done, If you have cast pistons/some wear present then can be louder when good and hot. The 600 engine was well known for it as you probably know but had both cast and forged over the years. Hard to generalise but forged pistons are more likely to slap when cold and hopefully reduce when warmed up but not necessarily if wear present. I haven't managed to find piston details/years yet.
Thanks Chris, that's interesting. It's a 1991 and has 48K on the clock. I assume the internals are original. I don't have any history as sadly the previous owner had died.
