FSE 450 valve lapping?
 

Going to pull my 03 engine down soon to give it a new lease of life. Does anyone know if you can lap valves in against seat with carborundum paste as you can with car engines etc. Maybe tiny bike valves more exotic material and cant be done like this. Any info appreciated.

Yes, you can. But, multi angle valve seat machining is always better.

Thanks for that, machining sounds expensive! On tight budget but will try and find out where in UK can do it and how much. Family/kids costs etc come first as always so have a feeling the grinding paste may be out! just need to keep it rolling for occasional play.

You need to take a good look at the seats and the valves, if the seating width is getting "too wide" you need machining of seat and valve, but if it's still within spec. just lap it with paste and it's all good:)