MOT Pass and richness.

[alanworland]

Just got a ticket for another tax free year!
While I was in the testing station I asked the tester If he would measure my exhaust emissions and he said it was running rich (about 9.5%) and asked if I wanted to adjust it while under test. I declined because in my experience the Morris does tickover a bit on the rich side, once under way the mixture is ok, as indicated by good plug colour after a run.
Is this what others have found? I am doing about 34/38 to the unleaded gallon.