Posted by andrew on September 09, 2002 at 20:56:21:
In Reply to: checking valve clearance posted by TomCat on September 09, 2002 at 06:55:32:
Hi TopCat,
Just like to say I thought your TV show was great. I was wondering what you were doing now!
I remove the small round inspection cover (about 30mm diameter) by finding a thick washer of about 40 to 50mm diameter. This washer fits perfectly in the slot in the inspection cover and can be turned using grips.
With the tank, valve adjuster covers (2) and the spark plug removed I slid a long (about 300mm) thin piece of wood down the sparkplug hole until it touched the piston. Then GENTLY turn the engine clockwise using a 17mm wrench on the alternator rotor bolt. The thin piece of wood will move up and down with the piston. YOU MUST BE GENTLE. IF YOU SNAP THE WOOD, YOU WILL HAVE TO STRIP THE ENGINE. When the piston is at the top of its stroke, feel the rocker arms for clearance with the valves. 0.08 to 0.13mm (0.003 to 0.005in) isn't much, so feel carefully. In fact it's at tiny gap you could easily miss. If there is no gap, rotate the engine 360 degrees (1 revolution) until the piston is back at the top again. This time there will be a clearance to measure.
When my bike is at T.D.C.,the mark on the alternator rotor points to the rear of the bike. Being used to bikes where this mark points straight up at TDC confused me at first. Thats why I used the thin piece of wood.
Once you have found TDC, you can check where the mark on the rotor is pointing so you don't have to use the wood next time.
I hope this helps.