9e/32a engines

[Vexis]

Well I've a few questions that might be able to be answered here easily ,
Been looking at my old log book and things don't seem to be straight forward. First it states mine as a 24 TDS,but the colour as black and red,the frame number as 61/1541.this is the continuation book from 1976 era.im assuming that the colour change was done after originally bbuilt? Now it is moorland blue and silver.also the engine I thought was a 197 cc 9e ,but looking at the identity for the frame number looks like it should be a 32a 250cc. Any ideas as to which it should be originally? Also what's the main difference between the 9e and 32a.cant seem to find any comparisons as yet? Certainly looks almost identical in photos I've seen so must be some internal difference I guess, how does the 197 and 250 vary ? Is it the cylinder and head length or is it a completly different stroke length / piston size?

[John Wakefield]

The 9E & 32A are from the same 'family' many dimensions the same ie stroke is 72mm on both engines but 9E has a 1/4" shorter con rod than the 32A.
You can fit a 31A 246cc barrel on a 9E crankcase as it is a shorter length (thinner flange) to accommodate the shorter con rod. These are hard to find these days but a quick & effective way to make a 9E into a 250. The 31A & 32A are both 66mm bore the 9E is 59mm. You would also need the head off a 31A or 32A to complete the conversion.
Your bike is a 24TDS & should have the 32A engine.