Timing belt yanmar 6LP
On the cylinder head above the injection pump / lifting eye the water manifold is secured by 2 nuts with washers an gasket that seals the manifold to head.
then half way down the manifold underneath there is a support bracket an the bolt 14mm or 12 head that needs to be removed .
Next on the exhaust manifold there's a rubber hose joint un do 1 of the hose clips an pull forward there should be enough room to remove the timing belt cover , make sure you drain the coolant down an remove any out of the manifold as this will drip / spew all over the belt an idler pulley an you don't want that .
Hope this helps