Two up top that are approximately four inches in diameter and sit six inches apart, leaving only about a two-inch gap between the pulleys, and then at the bottom of the engine, a small three-inch diameter rotating crank pulley. Because we have these two round pulleys at the top and one at the bottom, we have a guide on either side to hold that tension tight and then a rod that pushes against it to hold this chain in place.
The video we’re looking at shows the top two cams and that two inches between them. Where there should be no slack at all in the chain, we can deviate the chain more than an inch of motion. The factory specification for this chain says if there are more than 23 thousandths of an inch of play in the longest portion of it, it’s due for replacement. It says if there are more than 10 thousandths of an inch of play in the short section, it’s due for replacement. We measured the flexion at over an inch. This chain is stretched one hundred times more than the factory should have allowed.