No need to apologize, your tip about stiff motor was the clincher. I am grateful for any info. (even wrong info, 'cos it gets me thinking)
My original data sheet for the motors didn't even have the colours marked. I came across www.probotix.com data sheet for their motors that show the different configerations but could'nt be sure the colours were the same. When I applied the colours from the Zapp sheet that you sent me the link for, it all started to make sense.
So, now I think I connect Yell/Blk to A+
Blue/Red - A-
Brn / White B+
Green/ Orange B-
and if motor turns wrong way then swap A+ & A- around (or B+/B-) ?
Cheers Phil.