Low water pressure on Yamaha outbords

[evansmarine]

Any of you guys having issues with low water pressure when on plane or jacked up? We see this a lot with cat and tunnel boats losing prime/ pressure with Yamaha TRP lower units and Yamaha 4-strokes 115-300 hp.

We have a solution for this with the change of an impeller. We have made these modifications for years and have always had great results. This modification takes the cavitation out of the pump and allows you to never lose prime, also significantly boosting water pressure.

We can also modify the impeller and ship to you.

Call in and ask for Dillon for further details 281-559-BOAT (2628)

[plugger]

Thanks for the info .

[evansmarine]

The reason for modifying the impeller is to take the air gap out of the top of cup to make it a non prime pump. Taking the air out makes pump suck water even if you have water at lowest grate, it doesn't require full submerge to prime pump. Largest group it effects is shallow water and jack plate applications where you lift motor high to get full trim out of shallows or running super skinny with JP all the way up. On stock pump if you get top grate out of water, the pump sucks air loosing prime causing cavitation and no water pumping. New SHO motors are low pressure and you will not notice much pressure on gauge as its regulated, but they also are 1 of the main pumps to cavitate even in turbulent water near lower unit.

[kenny]

Bryan,
I remember someone telling me that Yamaha water pumps are electric when started then centrifugal once they're primed. Is that correct?

[evansmarine]

Absolutely not! They all run off Drive shaft only.

Bryan,
I remember someone telling me that Yamaha water pumps are electric when started then centrifugal once they're primed. Is that correct?