Better to give an example of what I am talking about.
If you have two series each with their own Y axis.
In series 1 all the values are between 400 and 500 and series 1 is on the primary Y axis. In series 2 all the values are between 100 and 200 and series 2 is on the secondary Y axis.
If you try to use auto range set on both Y-axis you get a range of 0-600 on both even though the only values that are plotted on the primary axis are between 400 and 500 and the only values plotted on the 2nd Y axis are between 100 and 200.
It should be something like the primary Y axis has a range of 350 to 550 and the second Y axis has a range like 50 to 250. I am attaching a SS of a chart that is set up like I said and also the source code to generate it which just modified your example. I tried moving things around without success.
Thank you,
Jon
MultAxisExample_147.zip