Alternative flush system using same panel and tubing....

[gbgrady208]

I've struggled with the plastic engine flush system on my Marlin 300 - - both broken parts and generally difficult to get the connector to plug into the valve. While GW did replace the parts that failed under warranty, I decided to look for a better engineered approach. For clarity, it needs some kind of valve to maintain it as a closed system when the engine is running. I was able to locate everything I needed on Amazon in Stainless Steel, picked up a new plate on Ebay for about $15.00 and installed everything today. I'll see how it holds up, but my post-modification testing was all positive - - no leaks, fit in the standard mounting plate and I now connect the hose directly with no adapter necessary. Photo is attached - - the brass caps are just added safety if the valve were to fail or if something rubs on it and opens it. Here's the parts list from Amazon if anyone is interested.....

https://www.amazon.com/gp/product/B098L9FFFL/ref=ox_sc_saved_title_2?smid=A2Q5DK7IXTJEDM&th=1

https://www.amazon.com/gp/product/B07LDQ3NTH/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B08BLC9P6D/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

And, if you happen to use the beduan stainless spigot toss the poly washers that it comes with and use rubber hose washers. The poly washers provided aren't sized correctly and push into the valve causing leaks. Once I tossed the supplied washers and used the extra rubber ones from the brass connectors everything was fine. I did use teflon tape on all connections.
Not pushing this on anyone, just sharing an alternative as I've talked to a lot of GW owners who struggle with the GW flushing system and/or dislike the need for the adapters on the hose.

 

[Halfhitch]

Very nicely done! Too bad Grady Engineers don't have your skill and desire for quality hardware.

 

[Hookup1]

Very nice. I have my own version for older boats. Melnor quick connects. Unsnap and plug hose in. Home Depot $4.98.

Internet #203136407​

Model #11MQC​

 

[seasick]

Keep us informed about the durability and operation. Interesting mod. My only concern are the brass couplers.

 

[gbgrady208]

The Melnor approach (or similar off the shelf) is great for older boats. However, those that have the flush panel with Colder (brand, not temperature) setup need something a bit more sophisticated to maintain the same concept with better durability and easier use (including directly connecting the hoses without adapters). Relative to durability and for clarity, all of the attached components attached to the boat (valve, hose barb, etc) are stainless, not brass. The only thing that is brass is the caps that are there just in case the stainless valve were to be accidentally opened with the engines running (someone hits it walking to the swim platform, crab pot pushes on, a big fish slaps it (let's hope), etc. I did use brass couplings on my dock hoses to get the right connection for this setup on the boat, but those are on the freshwater side of things. For clarity, everything I used that touches or has constant saltwater contact is stainless (304 - - could not find anything made with 316). If the stainless valve were to fail, the caps will keep it as a closed system until I can address the issue.

 

[seasick]

I get your point that the caps aren't a concern but should add that fittings that have constant contact to salt water should not be stainless

 

[gbgrady208]

Got it - helpful input for my future projects. The stainless parts in this only have contact with salt water while the engines are running. As soon as the flushing process starts, they would only be in fresh water until the next time the engines run and water re-enters the tubing between the valve and the engines. If the stainless doesn't hold up, the same approach would be possible with brass fittings and they are more readily available. Here's my take - - I was lucky that when the plastic fitting broke (or should I say exploded into many parts) that it did not affect the valve within the fitting. If it did, I would have been unable to run the engines until the repair was made. The stainless has materially lower risk of coming apart or failing than having the engine dependent on a plastic fitting and valve. It's my belief that the plastic was cracked when the boat was delivered new as that valve leaked the first two times it was used and completely failed on the third or fourth time it was used. Again though, I appreciate the advice on the stainless for other projects I've considered.

 

[SkunkBoat]

Only problem I have with it is that you have to screw the hose onto the fitting, and unscrew it...twice
You could add a Melnor type male hose fitting to the valves and put a female (shut-off type) connector on your hose.
Put a male fitting on your hose spray nozzle.
Then you could pop off the spray nozzle and pop the hose right onto the new valve.
You can get melnor type fittings in brass

the more I look at the picture I wonder how you connect a hose. Isn't it the "wrong end" of the hose?