ORIGINAL: acerc
I have three as well and have a couple guy's at the field that have gone to them. They all start first flip, idle well and seem stronger than expected. For example the 26cc specs call for a 18-8 @7100, I'm running a 18-8 @ 7400. Will almost hover my 17lb waco.
Robert, an MVVS 26cc with a JTEC Pitts muffler will do better than that, or 18x8 Xoar at around 8,000RPM on the ground
A proper Pitts muffler like the Silent Beauty muffler is far less restrictive and has better flow so you gain another couple of hundred RPM
They are also actual mufflers, not just cans