|Large improvements in power are possible with the
400 Scrambler engine. Below you will find both direct bolt-on
stages, as well as porting and our 400 Big Bore kit.
The stock 400 Scrambler engine has a wide powerband with a peak of 38 HP at 5750 RPM.
| Torquer Pipe:
Our Torquer Pipe has a wide powerband with strong bottom end performance and
maximum power of 43 HP at 6250 RPM.
| Top End Pipe:
The top end pipe produces strong midrange and top end power and still has good
bottom end pull. Maximum power is 48 HP at 6250 RPM.
| Stage 1:
Top End Pipe with a Boyesen RAD valve and a 38 TMX carb. The superior throttle
response of the 38 TMX flatslide carb is combined with the strong midrange pull a
Boyesen RAD valve.
Maximum power with the top end pipe is 52.5 HP at 6500 RPM.
| Stage 2:
Add trail porting to the top end pipe, Boyesen RAD valve and 38 TMX flatslide carb
and increase your output to 57 HP at 6750 RPM.
| Stage 3:
Full mod kit includes modified top end pipe, V-Force reeds, a 42 TMX carb and race
porting and delivers 61 HP at 7250 RPM.
| Stage 4:
440 Big Bore Kit has an 87 mm piston and trail porting. Combined with 42 mm TMX carbs,
V-Force reeds and top end pipe and you have 63 HP available, with a large improvement
in torque through the powerband.
| Stage 5:
440 Big Bore Kit with Race Porting. 14:1 Maxi Flow Head, Monster Reed cage,
44mm Carb and Top End Race Pipe. This combination delivers 75 HP @ 8000 RPM with a wide
torque band for hard acceleration.