2012 RXT-X 260 lost top speed

[RXTROYCE]

I had just purchased this machine, we did a compression test and a water test and everything worked fine. I took it out for 2 more rips and on the 2nd one when i took it out I lost about 10-15 mph on my top end.

ive been reading probably every forum i can find on the internet related to this and feel ive checked everything i can without taking the engine apart. Im a first time ski owner but mechanically inclined. I have taken this thing to the dealer and they say its immaculate and there is nothing wrong with it, so i am done with the dealer...

80hours on machne, riva stage 1 kit installed
oil changed and registers at 1/2 up curvature on stick
compression test before purchase and current is #1 123, #2 123, #3 125 with engine cold
top speed 60 (was 73) with normal acceleration
RPM 8200 (same as before)

things we have checked
-wear ring
-prop and shaft
-all hoses and clamps
-s/c clutch slip (no play at all)..there was a scant amount of oil residue in the intake hose though im told this is normal
-spark plugs are new with no residual on them
-IBR system is fully disengaging
-Boost builds to full pressure
-no codes
-all fuses and battery tested perfect

This has been a shitty issue since ive literally only put 1 hour on the machine since ive owned it so pls any help would be appreciated. There are no other symptoms other then loss of top speed, it accelerates great and all modes work great.

the only thing that had been done to the machine between 1st and 2nd run was filling up the tank with petro canada 94 octane.
I doubt its the problem but ive filled it up now with shell 91 and put some fuel stabilizer in and will test it tomorrow during a 20 minute ride to see if any changes are noted

 

[tubshooter]

Not an expert here but if you haven't lost RPM then it's not engine related I would think. It would have to be the pump or some kind of added drag.

 

[RXTROYCE]

Hey I appreciate it, gonna take the pump apart tomorrow and see what i can find.

 

[ht_addict]

I would check your carbon seal.

Check out the thread below.

https://www.seadooforum.com/showthread.php?39490-05-RXT-Loss-of-Power

 

[XP 787]

Full Rpm and boost leads me to believe its a pump issue or carbon seal/bellows. Check splines on driveshaft while you have it apart.

 

[RXTROYCE]

Thanks for the replys. Im gonna be dropping it off at the dealer tomorrow to get them to check the pump, carbon seals and my sensor as well. I dont trust myself to tear that stuff apart.

I had read that forum regarding the carbon seal prior it just sucks that the guy never mentioned if he found a fix...

 

[RXTROYCE]

*different dealer

 

[Coastiejoe]

Ok, even if the CS is bad, that is not your "loss of performance" issue. You will not lose RPMs due to a CS. You will lose speed and ski performance, but the engine could care less and you will still get max RPM's.

I see you say the plugs are new, but did you just look at them or replace them? 4-tecs LOVE their spark plugs.
All of you complaints lead me to believe that you have a SC and or SC related item issue. A hole in the hose, a hose collapsing, a loose clamp and or the SC itself.

You say there is no play in the SC. But did you physically check what the slip is with a torque wrench?

 

[RXTROYCE]

Ok, even if the CS is bad, that is not your "loss of performance" issue. You will not lose RPMs due to a CS. You will lose speed and ski performance, but the engine could care less and you will still get max RPM's.

I see you say the plugs are new, but did you just look at them or replace them? 4-tecs LOVE their spark plugs.
All of you complaints lead me to believe that you have a SC and or SC related item issue. A hole in the hose, a hose collapsing, a loose clamp and or the SC itself.

You say there is no play in the SC. But did you physically check what the slip is with a torque wrench?

Hey thanks for ur reply, the dealer had checked the s/c with a torque wrench from what they told me anyway. I had checked every hose and clamp on the machine with no visual issues.

I have changed the spark plugs twice now with no visible issues with any of them and the last set we tested the spark prior to putting them in.

 

[XP 787]

You stated that you are getting full rpm's so it is highly unlikely that it is an engine/supercharger issue. When you take off from idle to full throttle are you hitting the rev limiter or does it feel like a slipping transmission in a car?

 

[RXTROYCE]

You stated that you are getting full rpm's so it is highly unlikely that it is an engine/supercharger issue. When you take off from idle to full throttle are you hitting the rev limiter or does it feel like a slipping transmission in a car?

Yes it hits the rev limiter when i gun it smooths out for a bit then hits it again when my speed tops out.

 

[XP 787]

My rxp215 did almost the same thing. It would hit rev limiter accelerating but never hit limiter at top speed. Top speed used to be 65 then I changed wear ring and it went up to 69

 

[RXTROYCE]

My rxp215 did almost the same thing. It would hit rev limiter accelerating but never hit limiter at top speed. Top speed used to be 65 then I changed wear ring and it went up to 69

I wish mine was that easy, i hit the rev limiter on accel and top end

 

[ski-d00]

As others have said, if you are hitting full rpm but are 15 mph slower you have a pump type problem. Could be wear ring, impeller, carbon seal, etc. but unless you're towing a cargo ship behind you then that is the only explanation for loss of speed.

 

[RXTROYCE]

As others have said, if you are hitting full rpm but are 15 mph slower you have a pump type problem. Could be wear ring, impeller, carbon seal, etc. but unless you're towing a cargo ship behind you then that is the only explanation for loss of speed.

Ya im def in agreeance with you guys, the dealership is checking all those things and should be done by wednesday. I will let yall know when I hear back

 

[RXTROYCE]

Hey guys just wanted to update everyone. I got a call from the dealership saying my machine was perfect with no flaws once again. They said since its in there if i want them to try changing the wear ring so i agreed. 5 minutes later i get a call back saying we found your problem... I say yay. They said upon visual inspection my prop was fine but once they took it off the entire back side of it was bend and scuffed to shit. So they are gonna spend 30 minutes trying to fix it since its a $570 +tax prop but in the meantime does anyone know where i can get an inexpensive solas prop ? Or a recomended prop for top end?

 

[RXTROYCE]

So the shop was able to straighten my prop out for an end total of $214. The prop i have on is a solas 15/20R which they said is the best prop i can get for this machine. Thanks everyone for yoir suggestions and thread on.