Super Jet What would cause the pump not to hook up off idle?

Quinc

Quinc

Buy a Superjet
Location
California
Took the SJ out for her maiden voyage and giving it throttle off idle it just spins the impeller. I have to feather it until I am moving 2-3mph and then I can grab the throttle and go. Even if I let go of the gas as long as I am moving I can grab the throttle again and she hooks up fine and goes. Any ideas or things I should check?

  • 61x/61x 754cc Low end ported b y CPT
  • Coffman Sizzler opened to 47mm
  • Compression 190PSI
  • Solas 14-17 re pitched to 13-15 by impros (Dave said this pitch is like running a hooker 9/15)
  • Impeller has .010"- .009" clearance
  • Blue printed pump
  • Aluminum pump shoe
  • 61x plastic reduction nozzle
  • ATP freestyle Nozzle.
  • Tons of silicone around everything and all over the pump seal before install

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Quinc

Quinc

Buy a Superjet
Location
California
After way too much time on the internet last night I am leaning toward the mid shaft. Is there a way to measure/test the splines to make sure they are in good shape?
 
zimmy

zimmy

In my experience, the splines are either working or they arent, you will know when it had spun.

Sounds like a cavitation issue, probably sucking air somewhere. Check wear ring clearance or re-silicone (with a tougher product like ultra-black from advance) the pump seal etc.
 
Quinc

Quinc

Buy a Superjet
Location
California
Blowsion aluminum pump shoe. I covered it in 5200 and then screwed it on. It does feel like it is cavitating but I am not sure where it could be getting air from since it is under water?

Is this the stuff I should cover the pump seal with?
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TheBuzzard

TheBuzzard

Location
the jetski grave yard
all that silicone all over the grate and plate is unnecessary. put a bead of silicone in that crack in pic 2, where the rubber seal ring is. if the rubber seal is leaking, putting silicone on the inside will seal it and hillbilly fix the air leak. i'm sure thats where its leaking. i've heard if the midshaft bearing housing is bad cracked, it can suck air from the engine compartment.
 
zimmy

zimmy

Quinc said:
Blowsion aluminum pump shoe. I covered it in 5200 and then screwed it on. It does feel like it is cavitating but I am not sure where it could be getting air from since it is under water?

Is this the stuff I should cover the pump seal with?
22072.jpg
Click to expand...

there is more than one type, the one you have there is different.
the best one is the ultra black that has a thicker consistency and is a little grey in color. Check this link : http://www.waresdirect.com/products...kURL=froogle&gclid=CJ-lmemdpL8CFQIT7AodtVYAzA
it comes in an aerosol can or you can get it in a tube for a caulking gun from Advance Auto. Its the the best (Scottie Mac put me onto it).
Like Buzzard said, you want to seal the pump tunnel so that no air is being sucked in from the area surrounding the pump where your steering cable and water lines hang out. Ultra black on the black pump seal ring (both sides) and between the pump sections will probably do the trick as long as your shoe is mounted in there properly.
 
Quinc

Quinc

Buy a Superjet
Location
California
TheBuzzard said:
all that silicone all over the grate and plate is unnecessary. put a bead of silicone in that crack in pic 2, where the rubber seal ring is. if the rubber seal is leaking, putting silicone on the inside will seal it and hillbilly fix the air leak. i'm sure thats where its leaking. i've heard if the midshaft bearing housing is bad cracked, it can suck air from the engine compartment.
Click to expand...


I read all that silicone adds 1mph. So figured what the hell. =)


I took the pump apart and the pump seal was trashed, even the metal ring inside the seal it came out of it some how... I put my old blaster packing in there until I get a new one from JM, and she ran awesome!
 
mxmark4

mxmark4

Location
Knoxville
I took the pump apart and the pump seal was trashed, even the metal ring inside the seal it came out of it some how... I put my old blaster packing in there until I get a new one from JM, and she ran awesome![/QUOTE]


Are you talking about the seals for the pump bearings when you say pump seal? Got a blaster that feels like its cavitating after doing a spin or just taking off. Havent bothered looking into it yet.
 
Quinc

Quinc

Buy a Superjet
Location
California
The packing seal that goes between the wear ring and pump shoe. Your blaster issue could be the same or it might be time to send your impeller off for some refurbishing.
 
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