03-06-2008, 11:02 PM #1
1300 Recipe for 75! WHERE DID WE GO WRONG !!! HELP !!!
We just got back from the water. We were able to get ahold of JIM (THANK YOU FOR YOUR EXCELLENT SUPPORT AND CUSTOMER SERVICE !!!! YOU ARE THE MAN !!!!!!) After we spoke to Jim, he brought to our attention that the sponsons were stepped the wrong way. Once we fixed those we went back to the water and the ski went 64.9 mph. which was 2 mph slower than when it was jumping.
Here is a list of mods, that are supposed to be a good recipe for 75 + - a few mph.
Jims Head Milled
Jims FF plate
RIVA 1200 Grate
RIVA Trim Tabs
RIVA D Plate & Chip
RIVA Power Filter
RIVA EFI (settings 4437)
R&D 5 degree 87mm Exit Nozzle
VF3 Reeds From Island Racing (No Stuffers)
Pump Shoe filled with 3M 4200 Marine Silicone
Pump Reinforcement (fiberglass)
Oil Pump Block Off
These are items that remain stock on the ski
Exhaust Including resonator box
Last edited by MIARider; 03-06-2008 at 11:14 PM.
03-06-2008, 11:17 PM #2
what are your rpm's? are you hitting the 7400 limiter with the vf3's and stock prop?
Im just curious as my 06 runs 7320-7350 range stock and im sure the vf3's would put it to the limiter on the stock prop.
With the stock prop i doubt you'd see 75 out of it even with your other mods. But, i would expect to see at least 68+ with jims plate. Im sure others will ask about your pump shoe/intake maybe hanging to low or your wear ring being worn out.
Do you know what your rpm's are(aftermarket tach) are your powervalves opening all the way?
03-06-2008, 11:37 PM #3
are the riva tabs cut or stock? if stock they are a speed killer.
I am sure Jim covered shimming the plate and trim tabs.
what height did you set your pump shoe at?
Did you fit your grate to the pump shoe and remove any restrictions?
what rpms were you turning?
The stock prop will never see 75
There is a lot more to 75 than bolting on parts, it is bolting them on one at a time and recording the change. if it went the wrong way you need to see why. 75 and up is an investment in time as much as in parts.
03-07-2008, 12:10 AM #4
Change your EFI controller to 4-4-1-7. That will help top speed.
03-07-2008, 12:21 AM #5
If the ski is a 2003-2004 get a 2005+ HO pump with the 14/20 Dynafly. If it is 2005 plus just get the 14/20 Dynafly.
Also do you have a tach on the ski? What are your RPMS.
Your going to need a bigger prop, tuning on the ride plate, and the motor put together correctly to hit that 75mph.
I was hitting 73mph with VF3 reeds, intake, d-plate, and efi controller. This was with 1200 grate, ff plate, 14/20 dy, stock nozzle.
03-07-2008, 12:42 AM #6
Hello Eric, Check the pump shoe and make sure nothing is hanging or PM me a picture of the bottom of your ski. 64 plus mph. is pretty much stock for your ski, You have something major off causing that much speed loss.
Last edited by JIM'S PERFORMANCE; 03-07-2008 at 12:44 AM.
03-07-2008, 06:57 AM #7
Hey Jim, when you say hanging you mean lower than the haul? Ill post a pic as soon as I get home
03-07-2008, 07:46 AM #8
take a 3 ft straight edge and set it flat to the hull in front of the pump shoe
measure the gap between the straight edge and the pump shoe - this gap should be somewhere between .040 and .080 (the thickness of a nickel is just about right)
do you have the stock nozze, you try swapping out the 87 mm R&D nozzle and put the 85 mm stock nozzle back
03-07-2008, 08:05 AM #9
You really need to post your RPM's. A small tiny tach can be bought for about $40. With what you have in mods thats nothing. You really should be using a PET2100 but have to start some where.
Last edited by mrbtd; 03-07-2008 at 08:07 AM.
03-07-2008, 08:30 AM #10
wow thats a whole lot of no gain.
what is the compression of the head? did you test it after you put it back on from Jim, following the manual on how to bolt it back on properly with torque specs and steps? The stock prop is a speed killer at this point and that 87mm reduction nozzle is eating away thrust and adding more rpms that you prolly dont need right now. if your ski is 05+, put your stock nozzle back on, if it isnt, pick up an oem 05+ nozzle at 85mm. I am sure you can get one in the classifieds if you dont have one. what year is your ski? Did you set your plate as Jim said? Shim the front down, staying above the shoe, and push the back up. Did you grind down your pump and nozzle to get the plate up for speed? Before anything, I would pick up a decent tach. whether a Tiny Tach, or PET2100. We needs Rpm readings to go with your GPS'd speeds. If all else fails, backtrack. what did your ski run prior to any mods? 64ish is pretty much stock. My bet is your problems are down below, between the hull mods, and the pump area. I would put the stock tabs back on and push them up, dont shim them down if youa re stepping your stock sponsons. I would be sure your shoe isnt hanging BELOW the hull line, and your plate should be COMPLETELY above the shoe, at each stage, hull to shoe, shoe to plate, there should be a very minimal step, but that step should be upwards, not down. shim accordingly. when I installed everything, I grabbed a 4foot level as a straight edge. do not use a piece of lumber, 2x4, 1x4, etc... I would use a level or a metal straight edge designed for accuracy, do not improvise as it GREATLY affects handling and overall speeds if measurements are not accurate
Last edited by dogger; 03-07-2008 at 08:37 AM.
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