Type 4 - Other Internal Valves

    Linear Valves 1982 -87

    TCV Travel Control Valves 1986-87

KYB Linear Valve

The stock KYB Linear Valve is on the top. Some of these are adjustable, some are not. In either case the mod is the same.

Modified on the bottom. Cut the end of the valve off (as shown) and remove the internal parts. 

There are two types; adjustable and non-adjust. The adjustable type has an adjuster screw on the bottom. Do not remove the adjuster screw, just the other internal parts.

See also Standard Emulator Instructions.

SHOWA Linear Valve

Stock (top) - Showa Linear Valve as used in the DR350 (also CR and XR).

Modified (bottom) - The Showa DR350 Linear Valve can simply be dismantled (remove the nut on the top end and slide the pieces off). Do not remove the adjuster rod.

Enlarge the Compression Feed Holes

Damping Rods 17mm or larger - drill 8mm (5/16”) holes.
Damping Rods 17mm or smaller - drill 6mm (¼”) holes.

Enlarge existing compression holes and add holes if necessary so you end up with six holes (3 sets of 2 holes).

New holes should be spaced lengthwise above the existing holes at 10 mm (7/16") increments. Place each set of two holes 90 degrees from the last set so the strength of the rod is maintained.

The top rod is stock while the bottom is modified.

See Standard Emulator Instructions.

KYB TCV Travel Control Valve

    KX 1986-1987, YZ 1987

The idea behind the TCV was to increase the damping as the fork got deeper into the travel. The main fork spring sat on top of the TCV spring shown. A control rod going through the center of the damping rod is attached to a piston. This piston closely fits the ID of the damping rod. As the fork spring compresses the TCV spring compresses. The piston gradually shuts off a compression hole near the bottom of the damping rod making it stiffer. This only lasted a couple of years as the increased harshness deeper into the travel didn't outweigh the benefits.

Enlarge the Compression Feed Holes

Enlarge existing compression holes to 8mm (5/16”) and drill the TCV hole through to both sides. You will end up with six holes (3 sets of 2 holes).

Remove the TCV mechanism and install normally according to the Standard Emulator Instructions.