S1 Publishing(Oxford)©2007

World of motorcycleS
S1 Publishing(Oxford)© 1999-07
 Maintenance - Engines
Re-grinding - Valves
If you have checked you valve and know the could do with a re-grind, it isn't that hard to do, you will need a grinding tool and some fine grinding paste, which you should be able to get from any good motorist shop
1,  Smear a small amount of grinding paste onto the edge of the seat, making sure that you cover all of it.
2. Place the valve back into it's guide.
3, Wet the rubber end of the grinding tool 
4,  Place it into the valve you are about to grind. 
5, place both hands flat and rub them together, pressing towards the valve gently, and watch the valve turn about 1/4 turn and back, do this for about 30 seconds, then pull on the shaft of the tool, and pull the valve free from the seat, turn the shaft 1/2 a turn then repeat the rubbing process.
 Note 1: you will feel the paste work, when it feels smooth as you rub, it's time to use more paste.
 Note 2: when you want to check your progress, use a rag and clean both seats.

What should I look for 
Both seats should look very smooth and shine more than any other part. no little black marks visable. When that is done, it's time to rebuild the valve.  

This is just a general guide.
If you are about to do your own maintenance, using these pages, I take no responsibility if you get things wrong!
Modified for 2009