Raw Water Failure - and a Few Other Kinks

[Jetexas]

I just finished installing a rebuilt-from-salvage Phasor marinized Kubota Z482 2 cylinder in my 27' sailboat. It's basically a clone of a Beta Marine Bz482, and at this point I think I have half Beta Marine and half Phasor parts anyway.

The engine starts up and runs great, and my rebuild job on the transmission seems to give both forward and reverse. However, I'm not getting any water out of the exhaust.

I took the cover off of the impeller housing, and it's spinning. There's raw water in the line from the impeller to the heat exchanger, but I finally pulled the muffler off while it was running to see if any water was making it back into the exhaust, and there was none.

I did a vented loop between the heat exchanger and the exhaust elbow. I had to make the hoses long to keep them from kinking. I'm wondering if I overdid it.



I don't think I have a heat exchanger issue because I had the housing worked over by a machine shop, and I boiled the internals in an acid bath. Is it possible to install a vented loop backwards? Where is the water going? Did I just make it too high?

One of my other issues is that none of the gauges in the control panel work - only the ignition and the off button (the two new parts). I don't know if this is because the salvage gauges are all bad or if I have something wired wrong, but due to this issue I can't tell how hot the engine is running, so I'm scared to run it for more than five minutes at a time to see if any raw water eventually shows up in the exhaust.

I need some help on how to troubleshoot this.

YouTube - Beta Z482 Phasor Clone Test

[Ziggy]

It may be as simple as raw water pump needing priming. Try smearing a bit of silicon grease over the impeller blades before you start the engine. If that doesn't help check for the other possibilities, such us a blockage somewhere in the cooling system.

[shakey doug]

I am not familair with the phasor raw water circuit but i know the z482 beta circuit, have you checked the water supply plumbing for a restriction?If you have full flow at pump inlet check impeller centre is not turning on drive shaft when a load is applied. Remove hose from pump outlet and run into a bucket checking for full flow, If you have f- flow remove hose leading from anti-syphon at junction with exhaust elbow water injector maybe blocked ,if no water here check heat exchanger and plumbing for restrictions. The anti-syphon circuit and type you have fitted looks ok. Check all, do not take any thing for granted and start at the beginning and follow the circuit thru leaving the heat exchanger for last, hopefully you will find problem before then.

Good Luck, Shakey.

[JiffyLube]

I agree with Ziggy.

I installed a brand new Jabsco raw water pump on our engine once, and after installing it I ran the engine but no water come out. I opened up the pump and while there was some lubricant in the new pump, there was not enough for priming it (I would have thought a new pump would have come well lubed). I lubed the pump up real good, and this time the pump primed and water flowed.

[Jetexas]

I tried silicon on the impeller, cleaned my strainer, and then used the water hose to backfill the system. After doing all that, I only get the slightest trickle of water out of my exhaust at idle. I think maybe my impeller's worn out. Unfortunately West Marine didn't have one, so I'm out of luck for the weekend.

I'm soaking this one in water overnight in hopes it may swell up enough to pull some decent suction.

[r.furborough]

You may also have a worn coverplate in the raw water pump, they are important to seal the side of the impeller blades.

Also, assuming you have opened your seacock ;-) is it clear of debris or growth? Another possibility may be the hose connecting the sea cock to the RWP could be delaminating or collapsing through the suction.

[JusDreaming]

one time I decided to make a gasket for the impeller cover with real gasket material. Well it would not prime up!!!!! It seems that the gasket was too thick and did not allow the impeller to seat against the cover. The gasket needs to be paper thin. And as "Shakey" said I had a pump that the nut that holds the gear on the back had loosened and when the impeller was under a load it did not spin, but with no load/water, it would spin and look fine

[jackdale]

One other thought.

Check the cam inside the impeller chamber to see if it is worn. Been there, done that.

[Charlie]

I had a problem with my raw water. It would work fine and then when I would let it sit overnight it would stop working and no water would come out. I contacted a couple of mechanics and there advice was to lower the waterstrainer below the water line. When I did that the problem went away. There was a pinhole leak in the gasket of the stariner so that when it would sit for hours it would lose prime and then not be able to regain prime.

As such I would check all the intake fittings and make sure that there are no leaks in the hoses, the strainer, or the fittings. BTW moving the strainer below the water line cured the problem till I could get a rebuild kit for the strainer but it also meant I had to close my thru hull every time I turned the engine off.

[JiffyLube]

Since this is a pretty simple system if the pump is not the problem, then water coming in or going out has to be the problem.

Not to many things in a pump to check for. Check the condition of the impeller, check that the impeller screw is tight to the impeller shaft, check the cam and the cover plate for wear. If the pump is belt driven check belt tension and condition.

Maybe the intake through hull is clogged. Maybe the strainer is clogged. Maybe there is a pinch or obstruction in a hose.

If all that checks out good then remove the cover plate on the pump while it's still in place on the engine, shut of the water intake, and run the engine for a few seconds to see if the pump is actually turning.

[jackdale]

You can also check to see if you have water flow by removing the inlet to the heat exchanger and running the engine for a very short period of time. I have had to "suck" the water through the impeller pump on a couple or occasions.

[Jetexas]

I started at one end of the system and worked my way through to the other end. The only old hose was the one from the thruhull to the strainer, so I replaced that just for good measure. The thru-hull wasn't clogged.

I completely disassembled and cleaned the strainer. The basket was clean, but there was some mud in the bottom, so it got new silicone grease on all its seals and put back together.

I soaked the impeller in water overnight in hopes of swelling it up for better sealing.

I used a hose to test for free water movement through the heat exchanger. It was clear.

I then pre-filled all the hoses and reattached them.

I finally had water in the exhaust. However, it was like sprinkles of water coming out, not big gushes.

I think my impeller is just worn out. I'm ordering a new one today, so maybe we can finally get out next weekend.

[capt_douglas]

Either the impeller, the cam inside the housing, the gasket, or a bad connection come to mind. If the cam inside the pump is worn out, it won't allow the impeller bladed to flex enough to suck water.

I once had to get a dockside hose and cobble a connection together and run both the raw water pump and water to get all the air out of the lines and the pump working. Then I went back over every inch of the inlet side double checking the connections, checking hose condition, and that you've made sure the pickup side is as airtight as possible.

[Blue Stocking]

When re-connecting the raw water pump intake hose, give it a good squirt of dish washing soap. It helps the priming, lets you know when the exhaust system is passing a solid stream (medical term), and by the size of the bubbles, if there is agitation from excessive wear inside the pump.

[JiffyLube]

Originally Posted by Jetexas

I started at one end of the system and worked my way through to the other end. The only old hose was the one from the thruhull to the strainer, so I replaced that just for good measure. The thru-hull wasn't clogged.

I completely disassembled and cleaned the strainer. The basket was clean, but there was some mud in the bottom, so it got new silicone grease on all its seals and put back together.

I soaked the impeller in water overnight in hopes of swelling it up for better sealing.

I used a hose to test for free water movement through the heat exchanger. It was clear.

I then pre-filled all the hoses and reattached them.

I finally had water in the exhaust. However, it was like sprinkles of water coming out, not big gushes.

I think my impeller is just worn out. I'm ordering a new one today, so maybe we can finally get out next weekend.

If the new impeller doesn't solve the problem, then you're narrowing it down to the cam or cover plate.