Quite right. The manual says that you have to remove the throttle bodies in order to get to it, but I found that it is possible to get at the bolt if you probe around between the cables, tubes and heat mat. It is buried way down in the V of the engine, and you need a socket that will keep hold of the screw once it has been unfastened. The washer will probably never get recovered, so you will need a new one !
The photo shows my socket extension bar with the socket itself secured with red tape to prevent it from falling off. The throttle body inlets are covered with a broad clear adhesive tape.
Note that you don't have to tension the chain yourself. Once the screw is out, it gives access to a driver slot which allows the tensioner mechanism to be released. It is a helix which turns against a spring. As the chain gets slacker over time, the spring turns the helix which keeps the chain tensioner against the chain. The only way it can be made slacker is with the driver. Basically you only ever need to touch this device if you need to get the camshafts out (eg to change shims).
The screws that hold the air vents in place inside the air filter housing can be very tight. Get a JIS screwdriver, rather than Philips or Pozidriv. They are made for this type of screw and are much less prone to stripping the cross head.
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