Thread: Speed question GPR1300
05-27-2009, 09:09 PM #1
Speed question GPR1300
I used my Garmin etrex GPS for the first time (in my pocket) and the speed was only 56.2mph (almost falt water)
Pump Seal Kit, Tunnel Reinforced, R&D Ride Plate, R&D 800 Intake Grate,
Riva Sonsons (middle position), Premix (Amsoil Dominator 1/40), D-Plate
I guess my ski is a little bit slow for almost stock or? The speedo form the ski showed around 63mph which I thought is o.K, but the GPS speed is a shock.
Could the impeller and or wear ring be the reason for the low speed?
As far as I know nothing got replaced so far.
Motor has around 25 hours.
Mods in the next few weeks:
VFII's, 4*Key, Riva EFI Control Unit, R&D Power Flame Arrestor(are they safe to use?), Tiny tach
(Iridium plugs - no mod just a upgrade)
Still original pump and impeller but got a Nujet YM-C 6.5 but don't know if I can put it on without getting it repitched?
I got this impeller from a friend (new) but he doesn,t know either if I can use it with a almost stock ski.
Let me know what you guys think!
I'm thankfull for every advise I can get.
05-28-2009, 12:11 AM #2
I would start by looking for something hanging low catching water, ride plate, pump shoe grate etc. there is speed being scrubbed off this ski big time. Stock it should do 65 or more
05-28-2009, 02:40 AM #3
- Join Date
- Oct 2006
im with you bill, I am willing to bet its the pump shoe hanging down too low or plate catching....
05-28-2009, 08:21 AM #4
Nujet impeller will be fine
Just to be sure take a close look at the pump liner for damage while you have the pump out
05-28-2009, 08:23 AM #5
if you start modding the ski you should install anm aftermarket intake grate, I'd suggest a single bar R&D grate (don't use the double bar grates because they break)
waveeater clips (and not the couplers) are also a good idea
05-28-2009, 08:34 AM #6
Stock should do at least 62 mph. Like Bill said, many stock do 65 mph. If the engine is running strong, you probably have a pump problem (liner or impeller) or something causing massive drag (think pump shoe).
05-28-2009, 10:00 AM #7
05-28-2009, 10:35 AM #8
This is for me,what is the stock speed for a GP1300R I know the GP1200R was 62-63 mph Bill said 65 mph that sounds about right.
o uncola oStock should do at least 62 mph. Like Bill said, many stock do 65 mph. If the engine is running strong, you probably have a pump problem (liner or impeller) or something causing massive drag (think pump shoe).
Surely 62 mph is slow for a GP1300R 56.2 mph is not good.
What rpm are you turning are you still turning good rpm.
05-28-2009, 03:31 PM #9
05-28-2009, 03:41 PM #10
also maybe a power valve problem causing the loss in speed
can you tell what rpms the motor is running (yes I know the stock tach is very hard to read accurately)
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