Hi Welshy,
As per J, I have a mate who has ran his cougar with a 6.5 with no issues.
I will try it and start on blinky and see how it goes.
I must admit I did feel like you and was thinking around 8.5-9.5 but when the 6.5 was in it I thought go for it.
If it is too much I will certainly drop down.
I ran my RC10 all last year on 7.5 and 8.0 with no issues. The same mate had a 6.5 it that also again no issues...
Once I have tried it I will report back to let everyone how it went.