Pump cone deteriorating. Anyone seen this before?

[Adam4pt6]

I noticed an interesting situation with my ski and after searching on here I couldn’t find any similar posts so I figured it might be some good conversation.

ski: 2017 GP1800, stage 1 plus with a 13/18 solas. It’s gone 81.0mph(gps) at 8400rpms in less than optimal weather conditions(90ish air temp, 80ish water temp, high humidity) with a little less than a half tank and 80.5mph in slightly better weather(10 less degrees air, same water temps, much lower humidity) with a full tank but it was on the limiter. Note: the ski cavitates quite a bit on a hard take off from a stand still, hits the limiter 4-5 times and then pulls hard. Winter plans include pulling the pump and grate and ensuring the instal is done correctly and everything is nice and sealed up.

this is what the pump cone looks like

everything else looks fine from the outside looking in with an inspection mirror(impeller looks good, vanes all look fine, etc)

thoughts on the cause of this? I picked up the ski used and it was like this when I bought it.

I have a new factory cone on order and a lucky 13 cone on order as well. Once they come in I’ll report back with results with the new stock one and the lucky 13 in its various combinations (I will NOT be repitching the impeller or messing with the nozzle diameter as I have stage 3 plans for the winter and will be doing those things next spring, I don’t see any sense in going that in depth right now when the ski will only be used in this configuration for another month or two). My theory is the missing material may be causing a slightly lower pressure in the pump post impeller and may be the reason for the slightly high rpm for the mph I’m getting. I do find it odd that I don’t notice any other pump damage or hard cavitation signs besides the cone.

[BLASTER 1]

Seems to me that the previous owner might of been messing around with the cone or it was a really bad casting from the factory. Especially since you say there’s no other damage to the pump. Pull the pump and make sure you don’t have cavitation damage on wear ring and impeller edges

[Adam4pt6]

Seems to me that the previous owner might of been messing around with the cone or it was a really bad casting from the factory. Especially since you say there’s no other damage to the pump. Pull the pump and make sure you don’t have cavitation damage on wear ring and impeller edges

A bad casting is what’s making sense to me right now. I doubt someone would intentionally try to remove material, at least not with a result that looks like this. And yes, I’ll be pulling the pump for a more thorough inspection when the new cones come in

[Adam4pt6]

Seems to me that the previous owner might of been messing around with the cone or it was a really bad casting from the factory. Especially since you say there’s no other damage to the pump. Pull the pump and make sure you don’t have cavitation damage on wear ring and impeller edges

A bad casting is what’s making sense to me right now. I doubt someone would intentionally try to remove material, at least not with a result that looks like this. And yes, I’ll be pulling the pump for a more thorough inspection when the new cones come in