I have posted this topic in recent days but now I have new insight into my problem, which is that after I reinstalled my Series 1.5 4.2 l head after it was rebuilt, the upper timing chain is too loose and will not rotate when I rotate the crank and lower timing chain.
I believe I have now identified the source of my problem. This is the eccentric adjuster is not moving the idler gear up and down as much as it should. When I rotate the eccentric adjuster shaft 360 degres, the maximum up and down movement of the idler gear is only about 1 cm. By contrast, I estimate this vertical distance should be about 3 cm. As a result, the adjuster cannot pull the chain tight enough to engage the crank driven intermediate timing gear.
But why the too small an adjustment? My only guess, as I have not disassembled the timing system yet, is that the eccentric lobe is slipping on its shaft.
This is bizarre because the picture in the parts diagram suggest that the shaft and the eccentric lobe is all one piece. But I doubt that as it seems that it would be difficult to manufacture this as only one piece. But that is another guess on my part.
I would like to buy this as a new part and inspect if it is one of two pieces but can’t find a supplier that sells it.
Apologies for very long story but if you have made it this far, my requests for help/ advice are:
- Can you tell me if this part is one piece of two?
- Or can you suggest another reason why my idler gear does no move up and down as much as I believe it should?