Popping cleanout plugs like champagne corks on NYE... (Yes another thread)

[CauseTheImplications]

Just purchased the 2011 Yamaha SX240, (my first jet powered boat, after multiple IOs) Took it out on day one and the starboard side impeller manhole cover had a "forceful automated removal" breaking the latch on the hatch, and landing on top of it. So we came back in on one engine as slow as possible. Troubleshot, realized there were kill switches back there keeping the port side from starting.. fixed the latch, rebuilt the lower half of the Starboard side plug that came out, cleaned it yadda yadda, put it back in and got a good seat.

Well 2 days later, we took it back out, and the port clean out plug came 90% out, lodging at the top of the hole at 45 degrees, and we almost went the way of the titanic before I realized we were taking on water. Quick run to more shallow water where we found a courtesy dock at a restaurant.. we were heading there anyways so it worked out... I'm guessing 400 to 500 gallons of water made it in with the blow out ok maybe not, but enough to come half way up the motors and into the ski locker.

So since I had the parts on hand, I rebuilt the lower half of the Port side while the bilge pump pumped away. Cleaned it up, popped it back in to ensure a good fit. Hopped into the water felt around to make sure I didn't lose the actual bilge plug.. all good there.

I have a mechanic at the Dry Stack / Marina checking the other below water line seals.

So my go forward plan other than wait for a "Diagnostic" bill from Mr. Marine mechanic as a safety check...

1) Buy a second bilge pump just in case.
2) Pull the impeller clean out plugs next time I am out there and just clean the F out of them, and inside the housing where the dogs lock.
3) I bought the EZ Locks, just waiting on them to come.
4) I am going to follow some of the other recommendations and seal the "access hatch" way better than what it is.. (Ill post a follow up there, I am pretty crafty and building on what some of the other folks have done, I think I can give it a new spin)
5) Bought audible water / leak sensors for the bilge that Ill position around.
6) Add a couple of nerf footballs / noodles for good measure
7) Say a few Hail Marys
8) Try try again.

So why post this beating of a dead horse?

I am curious how much water can really come in, and end up in the bilge, when the second gen T-Handle type plugs blow out like that.

Does anyone have / has anyone seen, a Go-Pro video of a blowout in action? Any "Sea Chantey's" written about this that gives an idea of if I am making up that the water came from the blow out? There was a lot of water, and cant help but think this is a dumb design, but at least we didn't sink..

 

[Cobra Jet Steering LLC]

Do not place footballs on top of the clean out plugs the worst blow out is when the plug does not pop the hatches and shut down the engines but fills the engine compartment with water and that can get really expensive do research here the blow out plugs like you have were in use from the model year 2000 to 2016 in 2017 they changed back to twist in plugs remember the bottom of the plug is the bottom of the boat and there is a lot of force on them. The EZ locks were designed at the request of Yamaha jet boat owners who wanted an easy and inexpensive solution to plug blowouts and when the EZ lock stops a blow out you will know as the lock won't release until you reset the T handle and remove the pressure on the lock ends.

 

[CauseTheImplications]

Got it. No footballs / noodles. Bad advice floating around here as well. The locks are on the way, and I would second that if the second blow out would have broken the latch on the lid like the first, I would have probably noticed before the bilge filled up like on the second one. So are the broken hatch latches just something Yamaha JB owners with these have to deal with? That's the only way its going to open and kill the engine. The second one was still lodged in the hole at the top so it is as you mentioned.. bad..

 

[Cobra Jet Steering LLC]

The plugs you have were called blow out plugs and there is a ton of info on them . The person who talked me into analyzing the cause of the blow outs and coming up with a easy and inexpensive solution to this issue actually had a blow out when running W O T the plug blew open the hatch violently and launched in the air then it landed in the boat nearly striking his wife in the head. Just like the person who asked me to make steering for these boats way over 2 decades ago this customer brought me the plug and said find out why these blow out and please design an easy way to solve the problem.
As soon as I took the plug apart and saw the small plastic trey being contained in a track and being pushed forward by a small spring so that a round horizontal bar would snap into a notch cut in the The T handle shaft to secure the locking dogs in the aluminum ring to hold the plug in place I knew the issue was being caused by dirt that came into the plug body via the locking dog openings, these plugs always have water entering them from the pressure in the tube..
The water has sand silt etc suspended in it and when it evaporated it left the silt etc behind in the track to obstruct the forward motion of the tray thus keeping the round bar from going all the wat into the t handle shaft recess.
The solution was obvious and I still make the EZ locks as you learned .
You Put it on the plug, place the plug in the hole push the T handle down , when it goes down all the way the ends of the locks snap shut and keep the dogs in place . To remove the lock simply squeeze the lock to open the ends if the lock does not release you must reset the the Handle to release the lock ends.
This tells you the lock saved you from a blow out.

So once you get your locks installed you should be just fine.