Yamaha F225A Service Manual page 15

Tensioner
A timing chain tensioner is provided at the mid-span of the timing chain, between both camshafts.
The timing chain tensioner uses the force of a spring to maintain its tension. After the engine is
started, oil is pumped into the tensioner, and the resulting pressure causes the tension to increase.
A total of three tensioners are used, one for the timing belt, and one for each timing chain of both
banks, to maintain proper tension and to ensure the reliability of the valve train.
1 Intake camshaft
2 Exhaust camshaft
3 Timing chain
4 Timing chain tensioner
5 Hydraulic timing belt tensioner
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Features and benefits
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