Evolution engines have those @#$%^&* limiters installed on them.

The needles also tend to "walk" while the plane is in flight.

That means that while you may have the engine perfectly tuned on the ground, after flying around a bit, the needles will move, causing the tuning to go off during flight and you end up with deadsticks.

Last weekend a veteran flyer with a Pulse XT and an Evolution .40 was experiencing deadstick after deadstick, usually after 3-4 minutes or more.... though he had his engine fairly well tuned.

I walked over, re-adjusted his engine and placed wire ties over the clips to increase their friction against the needles and immobilize them.

I told him to fly.

I left after his fourth uneventful flight.

He called me that night to thank me for the quick fix.