Originally Posted by itchy b

First,
what size track are you running on and what level of traction/
If you run on a large trrack with med - high traction you could try a 1mm -1.2 mm on the clutch spring and .4mm -.5mm endplay using the Mike Swager clutch building method with either 17/ 23 pinions or if the track is really big 18/ 24 pinions will work.

This engine has loads of power and revs so try a couple of different combos and see what works for you best.