Hi Dave

I can't find any listing for S&J fuel, so cannot give you a comprehensive answer.
Between 5 - 15% nitro is fine, so that is not a problem. You mention it is a castor oil lubricant - do you know what %. This could be a problem as although we recommend some castor it is important not to use more than 6%. Anymore than this will cause the very rough running. In fact on the CD series, if you can't use one of our recommended fuels, we prefer you use a high quality synthetic oil.

I hope this helps
Regards
Laurenne