whoooott lipo

[Patrick]

Strange those batteries got so hot without other things getting hot as well. I guess you will need higher voltage.
If you were happy with the speed and power of that setup, then I'd get the 1515 2.5d (1650kv) for 6s. The rpm will be a little bit lower, but you can get the speed back easily with the gearing. I've used this motor a fair bit on 5 and 6s and I like it a lot. A 1515 1y will work, but I think you might just end up back where your were, over heating things. My 1y seems fast enough on 4s.

You shouldn't have to do anything different to a mmm to be able to use 6s.