Sounds like you got your issue resolved by gearing up...but perhaps you should take a look at your timing as well. Medusa recommends 8-15 degrees on their website for best efficiency.

In the Medusa section last week one person was having overheat problems running 036-060-2200 in a 1/8 buggy with low timing. Problem was resolved by changing timing to "Normal 10." Maybe something you could consider experimenting with.