Weeds - Big Time... Raw Water Pickup ????'s
 

Weeds are real bad this year in the Great Lakes. I guess we can thank the zebra mussels for cleaning the water so well...

I've got transom mounted raw water pickups, and I've had times when I've had a 4-course salad jamed in them. Burnt out an impeller last weekend, and constantly cleaning out the sea strainers.

Has anyone tried putting a coarse screen over the raw water pickup tubes on your transom? How did this affect your cooling at speed?

Also, what's your opinion on the best Sea Strainers? I believe mine are Perko, with a 2 1/2" x 6" long removable basket, round steel plate on top with a wing nut. They just seem whimpy for capacity. If I run over one floating weed bed, they're full.

Please don't suggest avoiding weeds, it's not easy. :(

Thanks,
Brian

Re: Weeds - Big Time... Raw Water Pickup ????'s
 

I'd be concerned about the screen cavitating and the engine over heating from the airerated water. I don't remember who, but somebody offered a strainer that was supposed to be able to grind the debris up so it would eventually pass through.

Re: Weeds - Big Time... Raw Water Pickup ????'s
 

I thought it was just me but yes it has been a bad year. I was out on Lake Ontario yesterday and have to negotiate a bay going out. I picked up seaweed going out and coming back. the flattened openings of my pickups are 1/4 by 2 inches. I didn't overheat. I saw the water temperature start to move, shifted to neutral, put it in reverse and goosed it a bit. Only other thing I've done in a situation like that was to immediately go on plane to force the weeds through. I've got racing sea strainers from Marine Machine. Covering the pickup opening with a screen might keep the sea strainers clean, but may block or reduce the flow of water to the raw water pump.

Re: Weeds - Big Time... Raw Water Pickup ????'s
 

Thanks guys, yeah my concern is also what a screen would do to normal water flow. My pick-up openings are about 1/2" by 1 3/4". I just spent tonight digging impacted seaweed out of the port side pick-up and flushing out the mess backwards. Then replaced the impeller, and dug out two vanes from my tranny cooler. Sucks.

I don't think throwing it in reverse would have helped this time. I try to check them whenever I putt in and out of some of the anchorages around here, and I emptied the strainers as well as felt the pick-ups with my feet while swimming around the boat. Nothing was there. When you're maneuvering around a hundred or so boats, you can't always pick the cleanest lane.

As soon as I started up on plane, I noticed the port temp climbing, and steam coming out of the exhaust. Strainers were full again! Emptying one helped, but not the port side. So I limped back to the launch, and once out of the water it looked like a head of lettuce hanging out of the port pick-up.

The macerator-type strainers sound intriguing. So what's all of that green stuff look like baked into the water passages of the block, and inside of the headers? I suppose green flow is better than none at all.

Sorry for venting, but these weeds are really getting old. It's getting to the point where I don't want to go to my favorite spots anymore, and the Mrs. ain't liking it very much. Maybe she needs to learn about strainers. Hmmmm....

Thanks again,
Brian

Re: Weeds - Big Time... Raw Water Pickup ????'s
 

I found this at west marine, but kind of expensive (1349.99 ea). Maybe it will give you an idea on modifying something else.

Groco Hydromatic Self-Cleaning 12V Raw Water Strainer
Forget about filter cleaning and leave it to Groco’s new self-cleaning strainer! Unlike passive filtration strainers, this strainer actually grinds and discharges debris, keeping water flowing freely to generators and air conditioners. One Hydromatic strainer will act as a sea chest, storing filtered water to be sent to water consumers such as air conditioners, heads and refrigeration systems.

User-selected periodic cleaning cycle
One-time manual override
Threaded 1 1/2" NPT inlet
Two 3/4" NPT and one 1/2" NPT outlet ports
13.5"H x 7.25"diameter

Re: Weeds - Big Time... Raw Water Pickup ????'s
 

Holy Chit! $1349.99 ea.? And of course, I need two. This is down the right track, but a couple of things concern me: 1) doesn't say anything about engine raw water, just air conditioning systems, gensets, heads, etc. 2) 1 1/2" inlet is nice, but outlet is only 3/4" NPT (x2). I don't think these would provide an adequate cooling supply to HP engines.

Thanks for looking.
Brian

Re: Weeds - Big Time... Raw Water Pickup ????'s
 

p4-33--I agree with you. Sounds like they probably don't flow a lot.--Lou