DISCONNECT THE BATTERY! Do not use the starter to perform any of these steps if you decide to use a positive piston stop method to determine true TDC.

To find Top Dead Center use a piston stop, to stop the piston in the same position on either side of TDC and take readings from a degree wheel. You will then split the difference in these readings and move the pointer this amount, making it the true TDC point. At this point. you can accuratly re-mark your vibration dampener and check cam positioning.

- Mount the degree wheel on the end of the crankshaft, and rotate the engine to approximate TDC

- Mount a pointer or use the current timing mark and line it up at zero on the degree wheel.

- Rotate the engine to move the piston down into the cylinder. Install your positive piston stop device into the spark plug hole and extend the bolt.

- Turn the engine slowly by hand, rotating it until the piston comes up and stops against the piston stop bolt. (having all spark plugs removed helps to make the engine easy to turn)

-Look at the degree wheel and write down the number of degrees shown by the pointer.

-Turn the engine by hand in the opposite direction until the piston comes up and stops on the piston stop bolt again. Go back to the degree wheel and write down the degrees it now reads.

-Add these two readings together (the sum) and divide the answer by two. (divided amount) TDC is at the center of the sum. The divided amount on either side.

Now either add a chalk mark on you dampener or move your pointer by this many degrees, or carefully loosen the degree wheel (without disturbing the position of the crankshaft) and move the wheel this required amount.

Retighten everything and rotate the engine again, making sure that the readings on each side of TDC are equal degrees away from zero. If they are, the zero on the degree wheel will now be the true TDC point. You can remark (punch or saw slot) your dampener at this position.

Be Sure to remove the positive piston stop device from the spark plug hole BEFORE reconnecting the battery.

Now that you have found true TDC , you can easily check your cam's position and adjust it as needed.
DD