Recently I replaced my cam chain, after putting it all back together I tried to balance the carbs, I had borrowed a carbtune, all seemed to be going ok until I tweeked a screw the wrong way, the balance got worse, but the tick over went UP !!
![Shocked :eek](https://foc-u.co.uk/Smileys/efocicon/shocked.gif)
. This made me suspicious of the gauges
![Wink ;)](https://foc-u.co.uk/Smileys/efocicon/wink.gif)
swapping pipes 1 & 2 suddenly showed quite a diffence, so I ended up trying to balance this pair by looking for the same difference when swapping and unswapping the pipes. Spent ages trying to set up a half way house. Then repeated this for 3 & 4, then between 2 & 3, I am sort of happy where I ended up
Since then I have got some T pieces and commoned them together, with the below result, here you can see 3cm of mercury difference between channels, the spec in Haynes is all to read within 1cm Hg.
So be warned, check your tool before using it