At the first go-off of my engine I noticed a rattling noise which seems to come from the exhaust valve. I discovered a slight sideways movement of the rockerarm and decided to remove the rocker box.
There is a clearence of about 3mm on the exhaust side (pictures) and clearence of about 1mm on the inlet side. The spindles, boxes and arms show no signs of wear.
After some research I found out that later models had a spring on the spindle between arm and box. Concerning the parts book this spring is not provided on my engine (built 1941). Besides I guess the clearence is not adequate to fit the spring.
Does anyone have any advice what to do?