Mike is right, these engines have a short, simple chain, but there is an additional reason that this engine has very long chain life. These engines have a ratcheting tensioner. As the chain wears, the tensioner takes up the slack and KEEPS the chain tight even during cold starts before the oil pressure builds up.

Many chain failures are on the engines that don't have a ratcheting tensioner. This adds stresses to the guides and associated parts while waiting on the oil pressure to come up. The oil pressure is what causes the tensioner to put pressure on the chain to take up the slack.

Good luck,