Hello fellow boating enthusiasts! I recently pieced together a raw water strainer/flusher for my 2007 22VE. Although my specific build was tailored to fit a specific space in my boat the procedure would be very similar in any boat.
I started by figuring out a rough idea of the design/functionality I was after and then looked around my boat for a good location that would involve minimal hard turns for the hosing and obstructions to other parts of the engine/trany/drive/etc. I wanted to have a strainer but also wanted to incorporate a place to attach a garden hose so I didn't have to crawl under the boat and mess with the fake a lake anymore.
Here's what I came up with for a design and also a part list and where I sourced the parts. I elected to mount it behind my rear seat in the engine compartment.
The only change to my parts list was that I sourced the brass hose bard from Fisheries Supply. It was a tad more expensive but discount marine supplies sent me the wrong size and when I called them about it they insisted it was the correct part. It wasn't.
I decided to save some cash by using schedule 80 NPT thread poly fittings for everything after the valve. Doing it in all brass will add at least 50-75% more to the cost. Everything is 1.25" inner diameter since that is what the water hose was.
The most expensive items were the strainer and hose. I couldn't find anywhere that sold the hose by the foot. Purchasing 12.5' from discount marine supplies was th cheapest I found it but you most likely only need about half that.
After I had it all ordered I stumbled on these...
After deciding on my mounting location I realized that there isn't any starboard(hdpe) behind that seat. It is fiberglass about 1/4" or so thick. This was a problem because I had planned on screwing it to the seat back. I took the seat back off and tried to figure out a way to mount it. What I came up with was drilling from the front then countersinking the holes for the stainless bolts. This presented another challenge as the mount for the strainer has only three holes drilled in it, two on the top and one in the center. I decided to drill two more on the edges so I had a good square mount. The problem I ran into was that my drilled holes weren't perfectly symmetrical so when I placed the strainer mount up to the seat back to mark the holes I realized it would need to be reversed. I got a piece of cardboard and marked the hole pattern on it then drilled out the holes using a bit the same size as the mounts holes. I then flipped the cardboard around and marked it on the fiberglass. I used the center seat cushion bolt as one of the top mounting bolts.
BTW, the seat back had 4 bolts holding it on. Three roughly equally spaced, then a forth that was hidden behind the carpet right by the walkway, I assume for extra strength in that high traffic area.
Here's a pic of the strainer/flusher after assembly. I used a small bit of 5200 on the first 1/4 inch of the threads for a good seal.
This garden hose attachment allows you to swivel both sides of it separately so it was perfect for this application.
The strainer itself is directional but you can flip it and rearrange the pieces to have the garden hose attachment on the opposite side if that makes it fit better in your boat.
After letting the assembly dry for a few days I bolted it in place and started on the hose routing. Getting the factory hose off is a bit of a chore. I used a small flathead screwdriver to push under the hose to break the seal. Between that and using a twisting motion it'll slide off. I attached the end to the water pickup, measured and marked it, cut it with a utility knife and a pair of wire snips(the hose is reinforced with metal to keep it from collapsing) then connected the hose from the strainer outlet to the drive the same way and fastened everything up with new stainless hose clamps(two on each joint).
Heres a couple pics of the finished install
A couple things I've learned since I started using it...
1-After removing the strainer bowl to clean it out, make sure the rubber ring seal is in place on the bowl before reattaching it to the strainer body.
2-Using the valve for flushing the engine. When you connect the garden hose you close the valve. Turn the water on, start the boat, idle for a couple minutes. After flushing the engine turn off the boat, then the hose, then reopen the valve to allow the water in the system to drain out the raw water pickup, then detach the hose and replace the cap. This way you don't get water everywhere and you'll never forget to reopen the valve prior to launching your boat and starting. I've heard a couple people say they've overheated their engine because they forgot to reopen the valve prior to starting the boat at the lake.
Cheers and happy boating!