Lower unit threads on 2004 115 hp 4 stroke

[tebbyfour]

Just bought this outboard this past summer and have just noticed the lower unit gear case threads are messed up as i was changing the oil to store it for winter. With the Yamaha lower unit drain only being an 8 mm bolt size, can i re-tap the threads to a standard 3/8 drain bolt like you would find on any mercury engine and use the mercury gasket and bolt for that size? Has any one had experience like this? What would other options be for this situation? Motor is 2003/2004 Yamaha 115hp 4 stroke. Thanks in advance look forward to your responses.

[boats.net]

You have to be carefull, the metal is not very thick abd easily damaged, then have to find a screw that the head will fit into recess properly.