Another Clean-Out Plug Thread

[anmut]

There's still the issue of backwash up the drains, but it's not nearly the frequency or severity, and I'd bet that's where residual water would come from if the tray is sealed and the hatch isn't leaking.

Agree with this. However, it's incredible how much water was being pushed past the plugs and into the boat. Come on Yamaha, do better.

 

[QuinJo]

I think the concern for most as well as myself is "why" is there water on top of the clean-out plug. I just took out my 2024 255xd and only have water on top of the Starboard Clean Out Plug. Is the cavitation is hear at times due to the plug not staying sealed and water passing by the plug? I like the design mindset behind the Clean Out Plug concept but am concerned with performance and durability if the Jet Pump Pressure is too much for these plugs.

I plan on putting a GoPro inside the compartment next trip out to get conclusive evidence of the origination of the water. I will post what I find.

So I sold 2 Yamaha FX jet skiis in order to have a family boat. The skiis had no clean out.. and I NEVER had any issue with cavitation.. while I like the idea of a clean out port, i believe the clean out port Is the cause of at least some acceleration cavitation... the following is my reasoning so let me know if you agree.. the impeller that pulls water( a serious suction of sorts) is aft of the clean out port.. with the power of the suction( not pressure as mentioned above) any possible breach of a solid water pull ( ie air drawn past the clean out port) would cause cavitation(slipping clutch) effect.. this is why if you back off the throttle (impeller suction) the impeller will grab water and accelerate.. therefor it seems to me that the port MUST be sealed of any possible vacuum leak in order to prevent cavitation issues on acceleration.. the fact that water gets past the clean out indicates it is not sealed.. And i agree the water above the clean out does not come from over the stern wash, its forced past the clean out.. in addition if you do have water above the clean out and you accelerate(assuming the clean out not sealed) the impeller will now draw down the water above the clean out, not air, therefor no cavitation until that amount of water above the clean out is gone.. Slow the boat down put pressure into the area if the clean out and now you get water back above the clean out.. I’m no engineer but have a good amount of common sense and i believe Yamaha had a good idea with the clean out but had poor execution.. After all these years they should have had a permenant fix… Not temporary bees wax.. shame on Yamaha