Shurflow Revolution 4008 rapid cycling problem

[rhyno76]

I have a 2012 Rockwood Windjammer 3008 and the water pump seems to cycle frequently (as in non-stop off\on\off\on\off\on) when using the shower or kitchen sink, but runs continuously when flushing the toilet or using the bathroom sink. The constant cycling results in a pulsating flow at the tap. Is this common or should I get in there and adjust the bypass and\or shutoff screws?

Notes:
Shower and kitchen sink are both further from the pump. The toilet and bathroom sink are relatively close to the pump. Also, Shurflo touts the 4008 as a pump that should not need an accumulator, and there's not really much room to mount\plumb one. I'd rather figure out whether this is just common (I should just deal with it) or if I should start monkeying around with the settings.

Thanks!

[rhyno76]

anyone have any tips?

[cfsoistman]

This is just a guess but the shower and sinks have aerators on them which restrict the water slightly so the pump briefly meets the pressure requirements to shut off and then back on as pressure drops. In the case of the toilet there's no aerator and the flow relieves the pressure for the total duration of the flush so the pump runs continuosly.
You may want to also check aerators at the shower and that other sink for debris.

[youroo]

There is somewhere to mount a bladder tank,the tank can be located anywhere in the cold water system downstream of the pump. Larger tanks provide long smooth water flow,without pump surge. Youroo!!