Indmar 340 Engine Block Plugs

[MOOMBA17]

Looking for some advice... I winterized my 2009 Moomba last winter with some help from a DIY video on this thread. When I drained the engine by removing the engine plugs, I noticed that they were corroded and the holes were rusted. I bought new plugs but still having trouble getting them in. How do I get rid of the corrosion in the hole? I was successful with one plug I think. How far does it need to be screwed in? Not sure this is far enough. See my pic for example.

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[DOCDRS]

Re-tap the hole. I always remove the plugs then put them back in after drainage and poking the holes to release and accumulated rust deposits

[VA LSV]

Use a 1/4" NPT tap and a little WD-40 to clean out the threads and then replace the original plugs with brass ones. Same for the v-drive drains. I just did mine this weekend.

[MOOMBA17]

Use a 1/4" NPT tap and a little WD-40 to clean out the threads and then replace the original plugs with brass ones. Same for the v-drive drains. I just did mine this weekend.

Thanks for the help here. Cleaned out the threads with the Tap and the brass plugs went in just fine. I was finally able to get on the water. Water still a little cold for my liking but should warm up this week.