Super Jet Cavitation

[rkm]

Im having a slight cavitation just off idle that Im having troubles diagnosing. Its not terrible, itll pull through it just fine and still has plenty of "pop". Just enough to be irritating.
replaced pump seal, no difference. Midshaft seals are new. Midshaft housing looks ok. It had the old style coupler with the center plug in it, replaced that with the new style.
Pump shoe looks fine, the only thing thats obvious to me is the pump shoe isnt centered around the wear ring, maybe a 2-4mm overhang. Its like the pump sits down too far(aftermarket hull).
Intake grate bolts arent sticking through the shoe.
Also my motor alignment isnt perfect, I need to redo that (I think the mounts sagged, it was perfect a week ago)

Any other ideas?

Setup-
Wammer hull SN
771, ported cases, 38s, B mod, stock electronics
Stock 61x nozzle, stock cone, 10/16 Hooker, Xr tech grate

 

[Matt_E]

The pump hanging lower than the pump shoe would worry me. I would look into fixing that first.

When I first put my mag pump in my Roundnose and sealed everything back up, I got a slight cavitation right off idle, from stand-stills.
Jetworks suggested that I may have sealed the rideplate to the hull too well and to try taking the sealant back off and possibly shimming the front of the ride plate down just a bit.
I removed the sealant, but didn't shim. And what do you know, the cavitation was gone.

How is that hull working out for you? Did you ever get it weighed?

 

[rkm]

Yeah I need to address that, havent quite decided if Im going to move the pump or clearance the shoe. rideplate had silicone on it but I peeled it back off.

Love the hull! It has the best characteristics of the old and new bottom decks. Its a little long but if I decide to keep it, Ill slap a new topdeck on it next year and shorten the hull. Never weighed it, feels light and thats good enough for me. Its way overbuilt and thats what I need. My last hull looks like it fell off the trailer going down the highway, but thats just from normal riding in the river.