Speedo calibration

[b3lha]

I changed the face on the speedo last night but I'm not sure how to calibrate it. I had to pull the needle off to change the face but it seems to be tricky to get it on in the right position.

First I stuck it on reading zero, but when I turned on the ignition it jumped up to 40mph. Then I pulled it off again and stuck it on zero with the ignition on. But then after going up it would stop at 10mph on the way down.

After many attempts I finally got it to a position which seems approximately right by pushing it on about quarter of an inch below the zero peg and then lifting it up over the peg so there's just a small amount of spring holding it down on the peg.

I'm sure that there must be a more accurate way of doing this, does anybody know how?

Phil.