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

 

[AmesJainchill]

Testers are needed, here's hoping for more reports of success.

I picked up some o-rings from MSC. Will see how they work for me and note it here. After doing the plug/gasket repair kit (F3F-67609-09-00) and the JBP riser the other year, I don't get any water in the bilge, but if I can keep water out of the tubes, even better!

 

[tdonoughue]

Anyone try the o-rings on the old style plugs? The non-screw-in type?

 

[drewkaree]

Anyone try the o-rings on the old style plugs? The non-screw-in type?

Some measurements might be needed for others as well, so if someone does try this, be sure to help everyone else and throw up the details. Measurements, what was used, where it was from, thicknesses and whatnot.

 

[FSH 210 Sport]

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

Except that there videos out there showing the clean out tubes with water flowing out of them while accelerating and underway.

The clean outs and the ability to clear what I’ll call soft clogs are what sold me on buying a jet boat, without those no way am I jumping in the water to clear weeds or a plastic bag.

Keeping the seals and the plugs in good working order, and keeping the areas where the seals rest in the tubes clean is a maintenance item.

Beyond clean out seals that are bad and or have dirty sealing surfaces, cavitation is caused by a severe pressure differential, vacuum on the impeller blades leading edge, Cavitation - Wikipedia


just like in science class where you put a cup of water in a vacuum chamber. Sir Charles Parsons discovered this with his ship the Turbinia which was the first steam turbine powered ship Turbinia - Wikipedia So, even when the clean out seals are good hammering the throttles at a standstill can produce cavitation that is unavoidable.

 

[FSH 210 Sport]

I received some O rings from @Spooky pantz and gave them a test fit yesterday…





When I installed the clean out plugs, it was reminiscent of how the installing process felt when my boat was new, firm downward pressure was required to be able to twist the locking handle. (Just replacing the seals with new ones made no difference). Looking forward to testing them next week!

 

[FSH 210 Sport]

10 hours of trolling and about a hour of full throttle fun throwing the boat around and nary a drop of water in the tubes…



@TeenGee

 

[drewkaree]

I believe the o-ring is sealing between the groove in the port and the bottom of the lip on the plug. It may also cause the rubber skirt on the plug to bulge slightly and seal against the wall of the port.
I think putting something into the gap between the rubber skirt and the cleanout plug will cause the skirt to rub as the plug is installed.

Thus far, it looks like many thanks are in order for @TeenGee discovering another fix for water entry.

If there's a cleanout drain (or drainS) on your cleanout tray, and you have a model where they have the molded "gutters" for the cleanout tray area, I'd say you have the absolute best design, with the addition of the O-rings @TeenGee found. I'd still add a check valve to the cleanout tray drains to allow any water to escape, while stopping entry that occurs when coming off plane and rushing up the drain tube. This would seem to be the only way left to get water in the tubes anymore, if you've added the O-rings. The theory that any water whatsoever comes over the back deck seems to have been debunked long ago with video, and I would put this in the category of old and outdated theory, but there's always the slightest possibility....

It's odd to me that the rebuild kits don't solve this issue. @FSH 210 Sport pointed out that when new, the OEM seals were much more snug, and the issue was at least not as pronounced as when the seals got some time on them and they wore. You'd think the OEM rebuild kits would return things to the original condition, but that doesn't seem to be the case. My theory is that the cleanout plug ears/tabs/wings or whatever you want to call them, simply wear with continued use, and no longer sit as low in the tube. @FSH 210 Sport also pointed out that the cleanout plug metal is of a softer makeup, which makes sense. You wouldn't want the fitting that's embedded in the fiberglass at the bottom to be the metal that wore, as that would be a nightmare and quite a spendy fix to replace those, so the cleanout plugs would be the eventual wear item.

At $170-ish EACH, that's still a tough pill to swallow, so hats off to @TeenGee for this find. A few bucks for some O-rings, and you can extend the need to purchase those brand new cleanout plug assemblies when they've worn to their end-of-life point, and if your plugs never sealed from brand new, like mine and many others, this seems to put an end to water filling the cleanout tray area.

I have a friend who purchased a 2023 brand new this year - old inventory that simply didn't sell. I'll be telling him that if I were buying a new boat, the things I would address right off the bat would be as follows:

1 - Buy the O-rings. If you don't need them immediately, you will eventually, so have them on-hand, instead of tracking them down later
2 - Buy and install a check valve on all drains on the cleanout tray
3 - Buy/DIY a riser. His inspection hatch is flat to the cleanout tray. ANY water in the area will likely leak through. Since you'll have to reseal it, why not add the riser while you're in there, and end any water getting in that inspection hatch?
4 - DAP Seal N Peel from @Babin Farms' suggestion, or silicone, for the entire edge of the cleanout tray.
*5 - forgot to add some lube to keep all the rubber parts from sticking and possibly STUCK in place

If you DIY the riser yourself, these 4 things will total somewhere around $100 or less, and you should have a dry cleanout tray area from jump. There's no way the dealer is going to do all of these things "under warranty", that won't cost you time, or possibly money (if you're forced to buy some of these parts so that they install them while @Yamaha dithers), or both. Even with a detailed list, and even possibly pointing them to this forum and the threads, if they have to ask @Yamaha if they'd cover it (which they UNDOUBTEDLY should), that process is simply not going to happen in a week, from the sounds of multiple reports, and could possibly take MONTHS of back-and-forth to get approval. IMO, spend the $100, do the work yourself, you'll know the quality of the work and the care you put into it, and you will be certain these things are ALL done.

This forum is absolutely great at coming up with solutions that can keep our members on the water more, and I appreciate all of the people who've come up with ideas and feedback to make our boats better. You guys rock!

 

[FSH 210 Sport]

Suggestion for the check valve for the clean out tray drain or any drain line.

Inline Scupper Check Valves - 3/4" - T-H Marine Supplies

Inline Scupper Valve / Check Valve A great solution to provide a scupper check valve in the drain line. Allows use of standard thru-hull fittings in the cockpit and on the hull exterior. Prevents Backwash Chemical Resistant Materials Thermo-Plastic Flapper Three sizes available for marine...

thmarinesupplies.com

Looks like West Marine has them in stock..

Double-Barbed In-Line Scupper Check Valves | West Marine

Check out our Double-Barbed In-Line Scupper Check Valves and more from West Marine!

www.westmarine.com

 

[TeenGee]

@drewkaree Funny that you and @FSH 210 Sport both mention check valves.....
I installed one of these yesterday. I had to wrap some electrical tape around and put a hose clamp around it to get it to seal.
I will be testing it next week and will report resutls.

1/2" Plastic Check Valve | West Marine

Check out our 1/2" Plastic Check Valve and more from West Marine!

www.westmarine.com

 

[jcb1977]

+1 on the o rings. Was out for about 3 hours today cruising about 35mph with some time wide open at 50mph. No water on top of the cleanouts at end of day.