[BIGKEV]

what you need to do, is find the absolute tdc of the #1 piston, and mark that on your pulley.

The best method in my opinion is teh "dead stop" method. No special tools or gauges are needed, and the result is accurate.

You see, one problem is that the piston stays virtually motionless while the crank turns over the tdc position. The crank keeps turning, but the piston doesn't move until the crank starts pulling it back down. This brief moment of piston wait, or "dwell", or "death", can last for several degrees of crank rotation.


The solution is to find the middle (in crank degrees) of the piston "dead" spot. Here's how:
You need to fabricate a simple piston travel stopper. Take an old spark plug, and knock the porceline center out. (bench vise, hammer, steel punch or something similar). Cut out the side electrode too. Then drill and tap the remaining metal part of the plug for a suitable bolt size, i use a metric m10 size.

Now find a long bolt that you can turn in and through the plug. You will need to have maybe an inch of bolt tip exposed on the other side, and enough threaded part of the bolt visible on the bolt head side for a jam nut.

This may take some trial and error, but next you need to "guess" how much of the bolt tip you want to protrude into the combustion chamber. Adjust the bolt accordingly, and lock it in place with the jam nut. I would also file the bolt tip round, because it will come into contact with the piston in the next step.

Now, screw your home made dead stop "sparkplug" in, while the piston is at or near bottom dead center. Nice and snug, almost as tight as a regular sparkplug.
Now slowly start turning the engine clockwise, until you feel the piston hitting your dead stop.. If the engine can turn a full turn without stopping, screw in your bolt a little deeper and lock it in place again.
Anyway. You have now managed to make the piston come to a complete stop against the bolt coming through the spark plug. Mark this position on the pulley. One sharp, thin mark right right on the outer edge.
Do not move your dead stop "spark plug" at this point.
Slowly turn the engine over the opposite direction, until the piston again meets the dead stop bolt. Mark this position on the pulley again.

Your true tdc is precisely half way between these two markings. Measure with a flexible tape measure along the outer lip of the pulley, or count the degree marks if you have a degree pulley to find that half way spot, and file a notch or otherwise mark your true tdc on the pulley, and rely on that in all your future adjustment procedures.