Ted, when the balloon "starts" to expand you are on the compression stroke. As soon as the balloon starts to expand stop turning. Now look to the flywheel so you can see the "pin" in the center. When this pin ti "vertical" you are ready to check the adjustment. Rotate the engine another 90* and you are ready for the next cylinders valves. Repeat this for all 4 cylinders and you have turned the engine 2 full revolutions.
If you error on adjusting error to the loose side of the adjustment not tight
.
If the balloon does not inflate we will need to look to the valves for TDC so they can be adjusted.
Dave Neptune