I had an engine go bad on my 4Tec Nitro and recently replaced it. I also replaced the plastic gears (some teeth were broken) and the clutch shoes (spring was broken and shoes worn).
I replaced the gears with the exact same parts.

The last Traxxas App telemetry run I did was in June and the max speed was about 70 mph.

In the same parking lot I made a telemetry run with the Traxxas App today and max speed was only about 50 mph

I think I accidentally changed the shift point. Maybe something else?

I don't know how to attach files to this post. So Here are graphs of the RPM and Speed from the June run
https://www.dropbox.com/s/zr04xb0xht...20RPM.png?dl=0
https://www.dropbox.com/s/y17jemibzf...Speed.png?dl=0

Today's RPM and Speed
https://www.dropbox.com/s/8lle1ed6p3...20RPM.png?dl=0
https://www.dropbox.com/s/vf0sy4m7lm...Speed.png?dl=0

Any help in getting back to better speed is greatly appreciated
Thanks