Bilge Pump Performance Apples to Apples

[K447]

More testing of the 800 GPH Rule vs T-H Marine ($29.00 Amazon) $39.00 Shoreline Walmart.
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Nicely done comparison tests, thank you.

We don’t know what voltage the battery was actually delivering during the tests but it certainly looks hefty enough.


About 55 seconds for the TH Marine to finish versus about 75+ seconds for the Rule, if I have my numbers correct from the YouTube timestamps.

That suggest the Rule is about 40% slower to pump the same 5 gallons of water. That is a rather large difference in flow.

And flow is what matters when you need to get a lot of water out of your hull!

5 gallons in about a minute for the TH_Marine bilge pump would amount to 360 gallons per hour. If it was flowing an actual 800 gph the bucket would empty in about 23 seconds.

The Rule pump in your test seems to be flowing about 230 gph, which is a long way from 800 ...

Clearly the gph number on the label is very different from the actual installed pump flow rates!


I will mention that float switches for bilge pumps seem to have a short lifespan in PWC, probably due to the frequent hull bouncing as you ride on non-smooth which repeatedly slams the float up and down in the dry hull.

My preference is for a bilge pump with electronic water sensing, so no moving parts other than the actual pump motor. I currently use the Whale SS1212 bilge pump, which is rated for about 1100gph through a 1 1/8” hose.

How much actual flow I am getting, I have not actually measured it

[TT350]

I would think the flow would increase as voltage goes up and decrease as it goes down. The difference between the pumps I think would remain the same.
As far as flow rate goes both pumps had over 12" or so of 3/4 ID hose to pump though and about a 12" of head and the hull fitting making a sharp 90 degree bend and it is about 1/2-5/8 ID.
If the pump wasn't pushing water uphill though a hose and hull fitting and was being powdered by 13.5-14.0 volts it may be closer to the 800 GPH mark.

I will say this, that T-H/Shoreline will keep up with a garden hose free flowing with no nozzle on it!

[Interim]

I was wondering for FX SVHO '15 model the stock bilde pump how it works. When I unloick the ski I hear it starts working ro about 20-30secs and then stops. When riding the ski, am not sure I can hear it (obviously as the engine makes much more noise). How this pump operates, start, stop, etc..? does it have any sensor to start working?

[K447]

I was wondering for FX SVHO 2015 model the stock bilge pump, how it works?

When I unloick the ski I hear it starts working ro about 20-30secs and then stops.

When riding the ski, am not sure I can hear it (obviously as the engine makes much more noise).

How this pump operates, start, stop, etc..?
does it have any sensor to start working?

My understanding is the factory Yamaha FX bilge pump runs when the engine is running, and continues to run for about 20-30 seconds after engine shut-down.

There is no water sensor, and no way to manually run the bilge pump with the engine off.

[Interim]

My understanding is the factory Yamaha FX bilge pump runs when the engine is running, and continues to run for about 20-30 seconds after engine shut-down.

There is no water sensor, and no way to manually run the bilge pump with the engine off.

thank you very much

[SL3STR]

this was helpful information...thanks!