AR190 top speed question

[2kwik4u]

I just purchased a 2018 AR190 and it runs at a max RPM OF 7600 (is that the stock limit) at 36/38 mph. If that's max RPM then a repitch could be on it's way, any suggestions?

Are you at altitude? Any signs of cavitation? What kind of load at that speed/rpm?

A tune can get you more revs. A reseal on the pump or L13 cone can get you more pump loading and less cavitation. A repitch might be in order if you're above 1k ft elevation.

 

[Christopher M VIllier]

Altitude 540'
No cavitation that I'm aware off
Full throttle, i can even back off throttle some and maintain 7600 rpm.
What does the cone do?
What affects do you get from sealing pump?

 

[2kwik4u]

I had pretty significant cavitation. I boat around the same mid 500''s elevation.

The aftermarket cone loads the pump more than the factory cone. This is accomplished by changing the volume of the nozzle (as a function of distance from impeller) to a more uniform profile. Hard to explain without pictures. It doesn't do much for a lightly loaded boat, but the more load you add the more consistent it remains, which is unlike the factory setup that is a compromise of letting the engine rev vs loading the pump.

Sealing the pump intake tunnel ensures that the pump only receives water and not air. Air can come from one of two places, leakages from the hull or boiling of watwr due to excessive low pressure. Both symptoms manifest as "cavitation" and it's noticeable when it happens. I had significant gains from sealing the pump, and it was an inexpensive project.

 

[Christopher M VIllier]

Thank you for the explanation, I will look into the L13 cone, what sealant is recommended for the intake?