06-14-2007, 08:19 AM #1
Time to work on the bottom of the ski
Ski is a 2001 12r - 145lb Comp, Open FA's,Rejet,VF2 reeds,05 Pump w/stock 14/20 (verified 14/20) Running a Jims FF plate and Shortened R&D tabs.
I know to clean up all the nicks/gouges with MarineTex.
Verified the grate/pump shoe is not below the flat spot in front of the intake grate (a nickel).
From 3" in front of the Intake grate back to the middle bottom of the plate I get a 1.287" measurement and there is no bouncing. Tabs are shimmed down with .50 washers (all 8 bolts).
Anything else to look at under there ?
I am @ 68.5-70.2 (on the seat) depending on fuel and conditions - RPM's = 7110 in the heat.
Ski accelerates hard, mid range is very crisp, plugs are good, PV are good.
06-14-2007, 09:39 AM #2
06-14-2007, 10:05 AM #3
Its a 1200 grate and 87 nozzle. I suspect that is 1-1.5mph diff and 40-70 rpm's.
I am ok with this but want to be sure the ski is "right".
06-14-2007, 11:43 AM #4
06-14-2007, 12:52 PM #5
- Join Date
- Jul 2006
06-14-2007, 01:00 PM #6
Thanks for the input...
No 2" extension. I am thinkiking I will remove the washers from the tabs and lessen the angle on the plate. Figure its a trade off either way and its free to try.
I need to fill some holes also.
Any other ideas ?
06-14-2007, 01:24 PM #7
It sounds like you're on the right track. Reduce the plate angle to close to .950", swap in an 800 grate, remove the shims from the tabs, plug all bolt holes, change to an 85mm nozzle and you're close to or over 73 on the buzzer in smooth water. If you haven't already, remove the bilge siphon from the pump nozzle for a bit more RPMs and speed, then work on truing your hull. Other things to consider: Advent CDI or 3 degree keyway, hole shot kit, 2" pump extension, removing trim tabs altogether. That should get you close to 75 and possibly in need of a repitch.
06-14-2007, 02:01 PM #8
06-15-2007, 05:48 AM #9
I have been wondering the same thing Brian.
Remember the old 95xp800 with the 2 inch pump extension. That thing use to porpoise bad at top speed. Then the 96xp800 came out and the porpoising was gone. It didn't have the 2 inch pump extension.
I have been wondering the same thing on the GPR's. But have not had time to swap out the 2 inch extension to see if it made a difference. I know everyone says its faster, but then I've heard a lot of bullshit being spilled out in the past.
06-15-2007, 06:59 AM #10
just food for thought:
I did back to back testing on removing the washer behind the impeller. with the washer gone so the impeller set back, I lost 1.4 mph at 74.2 . pulled it apart, on the ramp, put the washer back, and got 75.6 mph on the next runs.
This tell me the point of balance was changed? I am not sure. but I do not want a 2" extention to make my pump longer? Becuase I thing that would change my skis balance.
Now I run the old pump in my ski too..
This Is just what I rean across when playing with my pump.
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