I am a machine repairman by trade [yes a card carrying journeyman] and I agree that lapping your valves is best left to a trained pro. but if you insist on doing it yourself just remember the old oil commercial --you can pay me now or you can pay me later. if I had an old beater and the valves needed cleaned up I would go mild dish washing soap and then tooth paste [and I am used to working in the .001's] if it was a good horn I would pay a trained tech. I have never met Robert but he is right - I used to work part time in a music store and "home techs" and marching band made us money. old geezer Dave
