Yanmar Pleasure Boat Marine Engine Help

' V ' belt adjustment

Preferably use cogged v-belts 

Alternator belt adjustment - (the same principle can be applied to all belt driven equipment)

The total belt deflection should be 5 to 6mm or 0.25inches.
Do not overtighten the v-belt with a long bar or lever. The belt will wear quickly with associated black belt dust around the engine room, it will also come loose and in the worst instance the crankshaft will break.
Any misalignment will cause premature wear of the v-belt (s).

To adjust the alternator belt loosen the adjusting bolt and the pivot bolt, pull the alternator as hard as possible to tighten the belt, nip up the adjusting bolt while applying the force. Tighten the pivot bolt and tighten the adjusting bolt. ( you will need 2 spanners for the pivot bolt )