Be aware that there are several inherent problems with the Evolution engine as it comes.

- The ideal needle settings are normally outside the range that you can attain, as the limiters prevent good tuning!

- The needles tend to "walk" when the plane is warm and in flight!!!

This second problem is a biggie!

As you move the throttle up and down, the needles settings will CHANGE!

You need to cure BOTH problems.

- Pull the metal PEG out of the limiters. It will come out with a bit of force.

- Remove both needles and take the friction clips off.
- Bend the clips so they produce a stronger friction force.
- Re-install everything and re-tune.
- Once tuned, cut a piece of exhaust tubing to fit over the needles ( particularly the LS one ).
- Place the small tubing section over the LS needle to cause the clip to grip even more strongly.

This will prevent the problems you have.