Johnson Ballast Issue

[oh58plt]

Hey

I had a new thing happen tonight, out cruising around all is well decide to do some surfing. Turn on the pump for the port side fill all is going normal (maybe a bit louder than I remember). Start manually filling the front (winter project front filled. Notice that we are lot leaning over and the bag is sticking out of the locker. I have Johnson pumps above waterline drain and it worked great the last time out. The bag is filled with air and very little water, pull the fill line off the bag and water is only coming out in spirts not a steady stream.

Thinking bad impeller, get home. Tear it apart and it looks great. This is only the second time out on this new install. Tear the other side apart to compare and they look exactly the same. Both are Black impellers.

Any ideas? on what else to check.

Thanks

[chpthril]

Check-valves are allowing the impeller pump to draw air and not water. What style/model number check-valves did you use in the install?

[oh58plt]

I'm using the check valves that came with the wavemakers kit. I tore the whole thing apart and did not find a definite answer, I did replace the drain cv with one I picked up from west marine. Only cause there was maybe a trickle of air when I blew into it. Also the connection at the shutoff Valve was bit loose but the its on a barded connector so that could be causing it.

I did take it for a water test after putting it all back together and it worked good. Fingers crossed!

[chpthril]

Oh58plt,

I want to make sure I fully understand how your system is configure. As I understand it from a post above, you are diverting the drain flow to an above the waterline thru-hull?

If so, this requires 3 check-valves and 2 "Y" connectors in the plumbing p/sac. I am very familiar with the check-valves you got through wakemakers. If your system is configured how I outlined, then i completely understand the issue. I have had poor results with that style of check-valve used in that setup.

Regardless` of the pumps used or the configuration, it is very common to have a check-valve in the vent line. They can add in preventing passive draining as well as helping to achieve a more complete drain.

[oh58plt]

Mike
I will try and describe my setup better.

Yes it an above the water line drain thru hull. The flow is from shutoff valve thru a cv to a T fitting. The straight through T fitting flow goes into the pump and fills the bag. Then from the 90 degree off the T is a cv then out to the drain all on the same side. The vent line has a cv near the bag that crosses to the opposite side of the boat and the thru hull for the vent is up in near the front of the windshield.

So would you replace all the cv's? The cv on the vent line I have a hard time understanding since now isn't the pump having to work against a vacuum to empty?

Thanks for all your help
John

[chpthril]

Ok, so it sounds like you have a dedicated vent line with its own c/v. Thats perfect. Having it in the vent line is a good thing. It will allow the sac to raisin on itself as the sac empties. Since the sac is collapsing as the water exits, there really isnt a vacuum being drawn on the sac, until the water is gone. At that point, your drain flow drops off and you can see and hear the sac is empty and you shut the pump off.

I wouldnt replace them unless the priming issue continues. If it does, its going to the 2 in the fill/drain plumbing, not the 1 in the vent. I found that style of c/v to allow air to be drawn past the rubber flapper. This air either prevented the pump from priming or it really slowed the flow rate as it filled the sac with more air then water.....as you discovered.