The seller will have an expectation of what it's worth, so ask what he wants for it and go from there otherwise you risk offering way over the odds, or maybe offering too less and offending him which may weaken your buying position.
He likes to play cat and mouse with me on prices but TBH always been more than fair with me .. I guess we both don't have clue, that's why I asked the question.
All of those kits have a special wrench for the 16mm locknut. Some models give a torque for this others don't but how the hell are you supposed to set with a torque wrench with a 'T' handled tool? You would have though it would have a half inch drive (or 3/8") adapter like HondaClassics sells.
The 175A sloper manual does not give torque for that special 16mm nut and the Haynes Manual gives a torque that is totally wrong (nearly double what it should be) so both manuals are sadly lacking. My CB250K manual gives it at as 23 foot pounds max. and so does the 400F so I used that figure.
