Rev counter issues

Hi all. I recently sent my 246 rev counter to be re-calibrated as it was not working properly. The engineering company have sent it back twice now saying that it is as accurate as it is going to get. My engineer has tested it as follows (test reading second/car reading first)

1000 = actual 1010

1500 = actual 1530

2000 = actual 2250

3000 = actual 3590

4000 = actual 4880

5000 = actual 6250


It is running of the back-up electrics (not the Dinoplex) and I was told this is why it was not working properly in the first place (rev counter calibrated for 3 cylinders on Dinoplex but we need it calibrated to 6 cylinders on the back-up)


The instrument engineers say that this is as good as it gets because the dial is 'non linear' and therefore will need to be re-screen printed.

Does this sound right to you? Anyone one else not running on Dinoplex have similar issues?

Thanks for any advice

 

Thanks Kevin. Can I ask a more specific question that hopefully someone can help me with - does anyone out there run off the back-up ignition system and have a rev counter that actually works properly at the upper end? If so please let me know your secret as this problem seems to have the finest engineering minds scratching their heads...