Cavitation & Weak Hole Shot

[losgates]

Hey all:

I'm not new to boating, but new to jet boats and to this forum. My 2015 AR190 that I bought last year is not preforming as expected. Bought a "little rough around the edges" boat with eyes wide open but newer engine with only about 100 hours. No complaints about this very eager engine but at the end of last season had trouble pulling up a 200 lb single slalom skier with obvious cavitation in upper RPMs as the boat struggled to gain traction. I initially attributed this to hull fouling which is an issue here along the nutrient rich Potomac River with overall degradation of top end and fuel consumption. Now I'm wondering after reading other posts if my problem is related to the jet drive. To satisfy my curiosity, I pulled off the outer housing and impeller with shaft to inspect. There is some obvious remains of last year's growth, but the overall condition of the impeller looks OK. No obvious chips or marring. The housing does have some pitting, as seen in the attached image, but not horrible.

Are the remains of the marine growth enough to affect perform? If so, what is the best way to clean?

There is a thin sheen of lighter-colored "schmutz" accumulated on the wear ring and forward on the inner surface of the housing. Does this indicate that the impeller/wear ring are out of tolerance and either or both should be replaced?

And finally, once I've rectified the impeller/housing issue, would an after-market cone help with overall cavitation on this model?

Many thanks in advance for any sage advice -- and hope you all are enjoying a pleasant Memorial Day weekend.

 

[d_coyne1984]

Pulling up a 200 guy on a single ski is probably going to be a difficult task for the 190 regardless of pump condition. There just isn't a lot of surface area on a single ski so it takes a lot of power to pull that much weight onto plane and then combine that with the lack of traction from a small single impeller. Starting from two skies and then dropping is probably going to be a lot easier on the boat and skier.

That said, basedon what I have heard from others with the 190 who have added a cone, it would probably help. I would definitely try and clean the pump housing and impeller better. I've never tried this before, but perhaps something like a soft bristle wire brush (I'm thinking brass) would work well without digging into the aluminum too much. Maybe a rotary tool attachment.