Martin,

You are right - it does show 47, but what you can't see because of the reflection is the 47/56. I guess the the difference in bore size has no effect on the head change...

Regarding the throttling problem - failing to throttle up without flooding off - this fault is apparent to some extent on both 56s and, despite trying everything I know, have not been able to cure it on the ABC. The ringed has only 15 minutes on it - it seems better than the ABC so far, but there is still an indication of the fault when opening the throttle. Hence the MVVS carb. The carb is a little small for glow at 7mm but we'll see how it works on the JEN diesel. MVVS make great carbs - the ones on my 91 and 49 work faultlessly.

One of the first things I did when the ABC was showing problems was to strip the carb - I did remove three twists of brass swarf out of the carb, but it did not make much difference. Even changing the carb to an old OS 45FSR unit that fitted did not cure the problem. I think they were meant to run as diesels...

I am going to try a larger MVVS carb on the ringed glow 56, though.

I'm looking forward to running the 12 - it's a very nicely made engine (despite the bearing problem). I am thinking about an electric Ultra Stick for it - seems about the right sort of size and the engine is accessible to get me into running diesels again.