Revo 3.3 engine problem

[What's_nitro?]

I'm no nitro mechanic by any means- but could it be getting too hot and causing a gap to form between the piston and sleeve due to expansion, which would lead to a partial loss of compression? That would cause the symptoms you are experiencing. I assume it starts fine once it sits for a while and cools down?

Oh yeah, a BL conversion would be a good idea, too!