Blue Crab 2,471 Posted January 8, 2021 Share Posted January 8, 2021 Still sorting out not-quite-purchased boat. Just not getting much water out exhaust. And water pump housing too hot to hold in operation. Mechanic assures me the housing should be cool as it sucks in 50° water. This is a brand new Sherwood pump. Boat isn't close by so I'm relying on broker's mechanic (nor do I have any real experience). Engine rebuilt 6 years ago. Seems to me that there was some reason (unavailable) PO put new pump on in first place ... and that issue has yet to be resolved apparently. Doesn't this situation scream of a blockage in water passages, plugged ex elbow or a collapsed hose? Thoughts welcome. Quote Link to post Share on other sites
longy 855 Posted January 8, 2021 Share Posted January 8, 2021 Yes. No water flow, culprit could be any where from intake thru hull to exhaust injector elbow Quote Link to post Share on other sites
sledracr 909 Posted January 9, 2021 Share Posted January 9, 2021 My diesel (Universal M25) had a lackluster flow out the exhaust, accompanied by a propensity to creep upwards of 185F over time. I pulled the intake hoses and found that they were undersized (1/2"), and half-blocked by accumulated crud. Replaced them with new 5/8" flow is healthy and temp stays right where it should. If that doesn't solve your problem, follow the path. Is there a raw-water strainer? If your boat is like mine, the next things to check are the hoses to/from the heat-exchanger, and the heat exchanged itself. Then the exhaust mixer. Quote Link to post Share on other sites
Blue Crab 2,471 Posted January 9, 2021 Author Share Posted January 9, 2021 Thanks guys. Mechanic says all working correctly now. We'll see. I've read a whole bunch on line about this simple system. I've run into the bad hose thing once before. I found a spare impeller aboard ... a positive sign of some maintenance. Quote Link to post Share on other sites
SloopJonB 12,631 Posted January 9, 2021 Share Posted January 9, 2021 So what was the problem? Quote Link to post Share on other sites
Blue Crab 2,471 Posted January 9, 2021 Author Share Posted January 9, 2021 23 minutes ago, SloopJonB said: So what was the problem? Won't know til Monday. I'm hopeful but I've been on the planet too long to believe a breezy "it's OK now." Will advise. There were couple of issues. In the ensuing investigations I've run across several mods to make right away. Not moving back aboard til Spring. Post was really to confirm that WP should be cool in operation. Seems obvious but ...? Quote Link to post Share on other sites
Foreverslow 496 Posted January 10, 2021 Share Posted January 10, 2021 Check inline strainer. and make sure handle on screen is not in line with inflow/outflow. I have had a family of tiny muscles trying to breed in the strainer and kill my water flow late in the season. If there is a Groko strainer prior to the pump, see if the cap has a cork washer under the lid. If so, replace with a rubber flat washer from hardware store for less than a buck. The cork ones harden over time and induce air leaks which can have a big impact on water flow as that pump is trying to suck water.. Quote Link to post Share on other sites
Ajax 2,988 Posted January 11, 2021 Share Posted January 11, 2021 Here's a tip- those Sherwood pumps suck. I discovered that the Moyer aftermarket raw water pumps for the Atomic-4 bolt right on. That's what I use. Moves a lot of water. Quote Link to post Share on other sites
Blue Crab 2,471 Posted January 11, 2021 Author Share Posted January 11, 2021 Whew! In the nick of time. Thanks all. Quote Link to post Share on other sites
Blue Crab 2,471 Posted January 12, 2021 Author Share Posted January 12, 2021 Well, mechanic said all is good with limited water flow ... ie, he couldn't make the engine overheat. Anyway, I own it now. Next time at boat I'll be looking for these issues and popping for a high dollar intake hose. On 1/10/2021 at 4:56 PM, Foreverslow said: Check inline strainer. and make sure handle on screen is not in line with inflow/outflow. I have had a family of tiny muscles trying to breed in the strainer and kill my water flow late in the season. If there is a Groko strainer prior to the pump, see if the cap has a cork washer under the lid. If so, replace with a rubber flat washer from hardware store for less than a buck. The cork ones harden over time and induce air leaks which can have a big impact on water flow as that pump is trying to suck water.. And continue on from there. Quote Link to post Share on other sites
DrBrewHaHa 1 Posted January 12, 2021 Share Posted January 12, 2021 I had a 4511 in a Catalina 30 and it never pushed much water. I never had a problem with temperature. Nice simple tractor engine and worked well. Easy to find parts for mostly. Quote Link to post Share on other sites
Blue Crab 2,471 Posted January 12, 2021 Author Share Posted January 12, 2021 4 minutes ago, DrBrewHaHa said: I had a 4511 in a Catalina 30 and it never pushed much water. I never had a problem with temperature. Nice simple tractor engine and worked well. Easy to find parts for mostly. Thanks. I've been all over the net and read several comments like this. Quote Link to post Share on other sites
Zonker 5,248 Posted January 12, 2021 Share Posted January 12, 2021 You can also easily unscrew the end cap on the heat exchanger (1 bolt) and check for busted off impeller blades there. Quote Link to post Share on other sites
SASSAFRASS 765 Posted January 13, 2021 Share Posted January 13, 2021 Some of the mixing elbows are ported with relatively small holes around the ID easy to check if fouled, also doesn't take much to foul a small shell and tube heat exchanger, would be more heat and low flow. Quote Link to post Share on other sites
Blue Crab 2,471 Posted January 13, 2021 Author Share Posted January 13, 2021 The 5411 is the early engine with no heat exchanger. The new water pump is the clue. Whatever caused the PO to put new pump on hasn't been remedied. The pump is hot to touch. If it should be cool ... I really hope it's something simple like that cork washer mentioned above. Quote Link to post Share on other sites
ziggy 6 Posted January 13, 2021 Share Posted January 13, 2021 I also had a C30 with 5411 and it did not push much water. No heat exchanger. Quote Link to post Share on other sites
Blue Crab 2,471 Posted January 13, 2021 Author Share Posted January 13, 2021 17 minutes ago, ziggy said: I also had a C30 with 5411 and it did not push much water. No heat exchanger. Any idea if the WP was hot or cool in operation? Quote Link to post Share on other sites
ziggy 6 Posted January 14, 2021 Share Posted January 14, 2021 I don’t recall, but I’m thinking it’s probably warm from the rotation of the impeller and also being mounted on the engine Quote Link to post Share on other sites
Blue Crab 2,471 Posted January 14, 2021 Author Share Posted January 14, 2021 10 hours ago, ziggy said: I don’t recall, but I’m thinking it’s probably warm from the rotation of the impeller and also being mounted on the engine Yep. Gots to be warm. Mine is apparently hotter than that. Thanks. I'll be starting on that problem soon. Quote Link to post Share on other sites
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