I modified my Evolution 26 GX with a carburetor that is the next venturi size up, this combined with a tuned pipe has resulted in a notable performance increase, This 26 has always been a good engine, but my altitude is always a detriment. It's in an Ultrasport 1000 so I was forced to use a 3 blade propeller due to ground clearance issues.

I'm currently at 5400 feet elevation, 91 octane ethanol free gas, synthetic oil at 40:1, Master Airscrew 16X10 3-blade. I'm getting 8160 RPM static, which is slightly richened from peak RPM. I may need a larger fuel tank, it emptied a 14 ounce tank quite a bit sooner than I expected, but more than half of this run the engine was on the rich side. I'll have to do more testing, but so far I'm liking it!

Try a Graupner 3blade, it may work better for you than the MA.

Agreed MA are not very efficient. I like Menz in 2 blade. Graupner Sonic or Graupner carbon are also very good.

Sounds like it's running well! Thirsty little booger though!


P.S. 60cc chainsaw conversion is running really well now she has a 75cc 3w can. Also thirsty and in a good way!