AJS & Matchless Owners Club

Hi all, I have just split 2 engines to change the bearings, both 350 G5 lightweight. Between the crank shaft bearings is a aluminium stator, inside of the stator is a steel ring which is locked to the shaft with a woodruff key.
Now, there are two holes on the edge of the stator, one which lines up with a breather tube that exits the crankcase at the gearbox the other hole below it is threaded and lines up with a hole in the crank case. Neither of these engines has a bolt going through the crank case to the stator.
So should the stator be free to rotate, as these two are, or should it be locked with a bolt ?

No it shouldn't be free to rotate as it is part of the timed breather.
The earlier engines didn't have a separate bolt for the stator. The breather itself locked the stator in place and was a hollow tube/bolt that went through the back edge of the crankcase into a hole in the stator... some were threaded at the stator end and some not. It sounds like you have a later stater. Others may be able to say whether the later stator will work with the early hollow bolt/tube breather.

One hole lines up with the breather outlet. The other (threaded) hole takes a bolt to retain it.

There are three types of breather set up... The early one had a breather tube which threaded into the casing where the other end of the tube was an interference fit in the stator. This type was prone to wear between the tube end and stator eventually causing a rattle which sounds like a big end noise. Type two had a breather tube threaded at the stator end so the tube was threaded into the stator and not into the casing, a lot better!! this type can be used instead of type one as long as you have both of the later parts. Type three sounds like the one you have where there is a hole for the breather but no tube in the breather exit hole through the casing but it had a bolt in the casing to keep this in place, this IS NOT interchangeable with the first two types as you will need the later engine casing. see my you tube clip of the worn stator first type... and my picture of the 2nd type

Here's a photo of the later type stator with two holes (043036). It is held in place with a bolt (020016) and washer (000011).

Thanks chaps, a bolt it is then. Also thanks Clanger for part number, I couldn't find it on my drawings which was what caused my confusion as to whether it was required.
Appreciate all the help.
Dave79