Class 86 is not working properly

[iGabriel]

I have bought the Class 86 along with the class 90 and the WCML. Now when I use the Class 86 it only accelerates when I have the throttle above 20%. But as soon it hits the 30 mph it stops gaining speed and the locomotive just rolls without providing power.
Who also had/has this problem and wants to help me?

[Phase3]

The Class 86 is a "tap changer" read page 3 of the manual. I also published a guide here: http://www.railworks.marleyman.co.uk/store/index.php?main_page=index&cPath=15&zenid=73933f55b11068fa5d9737260afe66f4 (requires free registration)

[Pethulla]

https://www.youtube.com/watch?v=NDJQXK3fj3w

[iGabriel]

Wow I didn't knew about it's handling, thanks for sharing the links!