Hi, am from kuwait i have my RXP 2007 i installed Riva Stage I on it, and am getting only 70mph and less, when it was Stock am getting ( 70 to 71 ) and now only 70 and less, what may the problem from, even i change my wearing ring.

i hope that i can get an answer

Are you using a GPS or radar gun to get those numbers or are you going by the stock speedometer? There's no way you are going to lose speed by going to a stage 1.

Hey RXP Kid,
You seem to have yours running really good-

UNBELIEVABLY, I am actually having the same loss of top speed problem...

2007 RXP215 34 HOURS
Stock I Had it GPS'd at 69MPH, consistently in the high 68 -low 69 mph range- as recently as Last fri 6/6.

I bolted on the stage one kit yesterday & HAD THE SS washers upgrade & new clutches installed in the supercharger...the boat will now only run 66.7-67.2...
My RXP was getting 7900-8000 rpm B4 the stage one kit.... and now am only getting 7820/7840 with one flash on the fastest pass of 7860 rpm @ 67.4- but just for a second and it was back down to 67.1 & 7820/40....
I am really surprised- my new RXTX w/22 hours and Stage one installed monday was getting 70.2 yesterday- and absolutely flying....

My question to you and RIVA Crew- and anyone else on the forum-

Is it possible that the resistence of new cluthes/washers etc, in the superchrger are causing this-- and after the rebuilt chrger "breaks-in"-- will my topspeed go back up ? I am thinking no more than a couple hours should be neccessary-- Has anyone run into anything like this before? And if so, how long should It take to "breakin" this charger ? Or am I off base and is the problem elsewhere ?

Also- The superchager washer upgrade I did was at the suggestion of many people- The machine was running fine- but I was told repeatedly by Riva and others that the ceramic washers would fail- so this was done as preventative maintenance, not because the SC failed.

Rive Crew & Anyone, Coments ?

Who did you supercharger work? I wonder if the work was done properly. Seems like it may be slipping early. I heard of this with Les Cooke C-Kit superchargers straight from the factory. After the clutch was adjusted properly RPM and boost came up along with speeds.

Other things you need to consider when testing is weather conditions and such. These 4tec engines LOVE cool dry air. Heat and humidity kill them.

Also maybe the 14/19R is a little too much prop for your riding conditions. With the RXP215 you need to be turning 8100 RPM.


But first I'd definately pull the SC and check the slip moment and make sure the washers and everything else was installed properly.

Hey RXP Kid

Well i toke my RXP to the workshop and they test the SC and it was 7psi not 10psi, so its given me the minimum power, so the problem is they wont change it on the warrnty because its not broken, and i have to Pay for changing the SC kits ( 827.95 USD ) to repair it...

So what can i do?

Thanks, RXP Kid,

Yeah - we are thinking along the same lines on this one. The Charger was rebuilt by JetTrendz in Port Richey, FL-- and they rebuilt many of these SC's and have done many of these boats. Stage 1,2 & 3,-- and have boats radaring in the 75 - 84mph range. Brett, the owner, has the RXP back and the first place we are going is to the SC to check the install/rebuild- good to see you r thinkin along the same lines as us.

The other thing we will do this week is pull the impeller back out and check it to verify it is, indeed, pitched right. Both Brett and I have heard of the occasional mismarked one slipping out the door of riva/solas.

On the good front, the RXT- X boat , now w/ 28 hours, is now holding 71+mph, with topspeeds as high as 71.5 mph. Wat a great Offshore Boat this is ! I ran from Port Richey to Crystal River this Sunday morning- 100+ miles round trip, and had a blast. 28 gallons of fuel, later- and with only pocket change left for beer....I still had a great ride-- and am thinking about doing Long Beach 2 Catalina and Back in July, for a fith time. I raced it 98,99,00, & 01 and was runner-up in Open Expert Class in 01'. The only thing that sucks is I have to find somebody to drive the boat and trailer the 2600 miles to Long Beach, CA- we shall see-

Anyway, Have a good one and will shoot an update in when I have one.

RXP Kid,

Well, that was it- SC slipping like mad.
And I was easy on & easy off the throttle - no chop- just running in smooth water - no hitting the rev limiter or anything.

Have you rebuilt yours and what breakin time / procedure would you reccomend ?
- I am being told the SC's always slip when newly rebuilt- is that right, in your expirience ?
- and that I need at least a tank of fuel through it prior to WOT w /a fresh rebuild with the SS washers..?
-your thoughts ?
Thanx.

Sorry guys I haven't been over here lately.

Q8RXP, that boost sounds about right for a stage 1 kit. The SC won't make 10psi of boost unless you are running a Riva Stage 3 supercharger at 8100 RPM. Where are you getting your speeds from? The stock speedometer or a GPS unit?

Offshore2, good to see you found your problem. There is no break in period after rebuilding an SC or readjusting the slip moment. Go out and ride it like you stole it. Running a full tank of fuel before running the ski WOT after a SC rebuild is BS. The SC will slip if you chop the throttle, come unhooked, or are bouncing off the rev limiter. I have never rebuilt my own supercharger. Since it's such a delicate piece I trust it only in the hands of professionals like Jerry Gaddis aka Green Hulk. I'd give you his contact info for his service but I don't want to post a service on Riva's forums unless it's ok with them. I know they're good friends with Jerry and they helped out with Mudbug this year but I don't want to offend them.