Type 2-8 Yamaha MX250 1975
 - 34mm KYB

This is the stock damping rod head. As you can see, the Damping Rod Head is brazed on. This does not allow the Emulator Adapter to sit flat. This will require careful machining. Note also that the Piston Rings are simple o-rings. These are commonly worn out and are a source of friction.

The Head of the Damping Rod must be carefully machined to 16.5mm diameter to provide a SMALL step for the Adapter. Only machine a 1mm long step as this is plenty for the Adapter to seal. (This one is a bit too aggressive.)

YOU MUST NOT MACHINE THROUGH THE BRASS AS THIS IS WHAT HOLDS THE FORK TOGETHER! IF YOU ARE NOT QUALIFIED TO DO THIS SEND YOUR DAMPING RODS TO RACE TECH.

The compression holes must be enlarged.  Drill the original holes to 6mm (1/4") and add two more sets above at 90 degrees to the last set. Carefully deburr.

The adapter is a simple sleeve that goes between the damping rod and the Emulator. Alternately there is an Adapter that has a Piston Ring built into it so you don't have to rely on the O-rings.

The main spring holds it all together.