02 RXdi will not go over 54 mph...

[my02rxdi]

Hi, I am new to the forum and was wondering if anyone could help me out with my problem. Last year I bought a 2002 RXdi which on my gps unit had an average top speed of 59 mph. In my quest to hit 60+ over the winter I intstalled a R&D intake grate, R&D ride plate, and an R&D 2.5 degree pump wedge. (it already had a solars impeller installed by the previous owner)
Today was my first full day out on the water, and although the ski did not feel slower to me, both my speedometer, and gps read a top speed of 54 mph. This was tested many times during the day, in choppy, and in calm conditions... I have no clue why this year the ski is 5 mph slower (and now it even has more performace mods) Speaking to R&D over the winter they claimed the ski should be in the 63 mph mark.
Can anyone point me in the right direction on this one? (at this point id be happy even going back to my last years speed of 59 mph) - oh, and btw, new plugs, and fresh gas (before anyone say's that could be the problem.) thanks

 

[griz400]

possibly that intake grate too agessive for your set up -- (prop - eng) -- and it just spring where you live, -- did you put on some winter weight -- (beans and ham and gravy)

 

[my02rxdi]

is that possible for the intake grate to be too aggressive? It does make sense, but i have never heard of that before. (the winter weight, well its only 4 pounds, so i hope that isnt the problem lol)
I guess i can put the stock one on, and try it out...

 

[99spxxx]

is that possible for the intake grate to be too aggressive? It does make sense, but i have never heard of that before. (the winter weight, well its only 4 pounds, so i hope that isnt the problem lol)
I guess i can put the stock one on, and try it out...

To much water for prop to push.. may need nozzles.. Plus wedge is to push nose down which will help you take off and turning, but make you plow more water at top speed.. Also have you check the wear ring.. They dry rot sometimes from sitting and crack.

Last one you GPS may have a better reading now... Never know..

 

[my02rxdi]

After reading up on the top loader intake grate I have seen that they sometimes do lower the top speed of a ski. I will test that out hopefully tomorrow when I get a chance to get out on the water.

I did do some other searching on the forums about other people having speed issues with rx models. Many times people said dirty RAVE valves can be the cause. I went out and removed mine, and I could not belive how dirty they were. (my ski has 65 hours on it, and I have never cleaned them since ive owned it.)

The attached picture is how I found the valves to be. It took not only carb bleaner, and a brush, - I needed to use a razor blade in tuff spots to get all of the build up off of them.

Can this be a cause of loosing 4 mph?????