OK a few little updates. Hi Mitch, keen eyes there! I scraped away a little bit of black stuff on the head and came up with this...
![[Linked Image from farm6.staticflickr.com]](https://farm6.staticflickr.com/5607/15317055498_3f651fd3c9_c.jpg)
Then I cleaned up the dirt from around the exhaust and came up with a hole which is I am guessing is the one you were referring to.
So it looks like a worthwhile motor to fix up.
Now the reason that I think that it is a conrod big end bearing is due to the amount of movement I can get it to do, and not in the proper direction

.
This is where it should be
![[Linked Image from farm3.staticflickr.com]](https://farm3.staticflickr.com/2950/15500560931_9a2ab29a5d_c.jpg)
But if I jiggle it a little, I can get it to move like this
This bearing needs replacing
![[Linked Image from farm4.staticflickr.com]](https://farm4.staticflickr.com/3949/15316996260_e823c22af1_c.jpg)
I need to find a bearing puller now and get the crank apart, I am guessing the bits of metal which came out of the crankcase are mangled bits of rollers.
B