Dealing with blue plastic drain plugs in VP marine engine

[Donald]

As I ready the boat for spring startup I screwed in one of those blue plastic drain plugs and it snapped. Then noticed the other one had snapped in the fall but I did not catch it. They are suppose to be an improvement over the brass NPT drain plugs?

Luckily there is a hole in the middle of the broken off piece that is stuck in the exhaust elbow. And it's plastic so it's not corroded stuck. But not a lot of room going straight down. Not enough for a normal size screw extractor. Ordered a set of screw extractor bits (maybe an inch long) and will see hot it goes with those.

Ok, I get it, these have a wing nut handle so no wrench is needed. But after both snapped I will need more than a wrench to get them out.

A company makes a SS replacement one for Mercruiser and will check with that company to see if they will also fit a VP. These seal with an o-ring and so are not NPT. Mercruiser and VP could use different threads. Metric vs SAE?

And why the hole in the middle? Makes it weaker I would think. But easier to get a screw extractor on the broken off piece.

 

[Wrenchturner44]

I am guess hole in the middle is from center point for injection molding process.

 

[Donald]

As I ready the boat for spring startup I screwed in one of those blue plastic drain plugs and it snapped. Then noticed the other one had snapped in the fall but I did not catch it. They are suppose to be an improvement over the brass NPT drain plugs?

Luckily there is a hole in the middle of the broken off piece that is stuck in the exhaust elbow. And it's plastic so it's not corroded stuck. But not a lot of room going straight down. Not enough for a normal size screw extractor. Ordered a set of screw extractor bits (maybe an inch long) and will see hot it goes with those.

Ok, I get it, these have a wing nut handle so no wrench is needed. But after both snapped I will need more than a wrench to get them out.

A company makes a SS replacement one for Mercruiser and will check with that company to see if they will also fit a VP. These seal with an o-ring and so are not NPT. Mercruiser and VP could use different threads. Metric vs SAE?

And why the hole in the middle? Makes it weaker I would think. But easier to get a screw extractor on the broken off piece.

I am guess hole in the middle is from center point for injection molding process.

Maybe but I am guessing the hole made them weaker and more likely to snap. The new ones I ordered are a superceded part number. Will see if they are different than original.