For Lap Fitting:
1- Remove handle from cone/plug by removing the set screw.
2- Find an Allen wrench or other device that will allow you to spin the cone rotationally 360 degrees. I am using an Allen wrench here as the "L" end works great for this.
3- Insert cone/plug and install the dog washer BACKWARDS with the dog facing away from the valve body.
4-Install flange nut and tighten so you can still turn the cone/plug with the Allen wrench.
5- Rotate the cone fully in a 360 degree fashion roughly ten times in the same direction.
6- Loosen flange nut, remove cone, wipe clean and check lapping progress.
7- If more fitting is needed re-apply a light layer of lapping compound and rotate the opposite direction approximately ten times and check again.
*******A Word of Caution********
The instructions from Spartan are very misleading for lap fitting. Folks often assume they want you to use the handle in a simple back and forth motion to lap fit. This is NOT the case and can result in ridges and uneven lapping. Spartan is aware that they need to change their instructions to be more clear and Paul had asked me to "override" their instructions here for anyone who might read them.
Lap fitting should always be done in a full complete 360 degree circular fashion and not a 180 degree "back and forth" manner...