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Discussion Starter #1
Hi all,

Just bought an 04 RXP with 114 hours with trailer for $2500. Didn't have the chance to test it on the water when I bought it but figured the price was good enough.

I checked the supercharger to see if it would spin freely by hand and found it impossible for me turn. So I then took it out on the water.

Thing runs great, no issues I could feel or see.

Well now that it's still cold, I want to get any maintenance out of the way.

I bought oil, filter, and spark plugs.

The previous owner said the supercharger was rebuilt at 100 hours, but has no documentation to back it up.

So... I will probably rebuild it to ensure that there are no issues down the road.

When I was looking at rebuild kits, I was curious what supercharger upgrades there are (since I will already be in there with everything apart).
I am new to the PWC world, but am no stranger to mechanics and have pretty much completely rebuilt the lower half of my 335i (larger turbos, new bearings, upgraded clutch, etc.).

So... What are my options that aren't crazy expensive to get more reliable power out of this bad boy?

Also, I saw some upgraded flywheel bolts on Riva. Is that a pretty good idea to replace as well?

Thanks for the help!
 

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Unless you are going to replace the exhaust valves and flywheel bolts, I wouldn't upgrade the power! The supercharger is just one flaw in this engine's design and manufacture. If you're comfortable with those replacements, then go for it!
 

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Unless you are going to replace the exhaust valves and flywheel bolts, I wouldn't upgrade the power! The supercharger is just one flaw in this engine's design and manufacture. If you're comfortable with those replacements, then go for it!
Thanks for the response.

What are the issues with the exhaust valves? Do the 255 hp skis have upgraded valves?
 

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What are the issues with the exhaust valves? Do the 255 hp skis have upgraded valves?
The early skis had hollow exhaust valves, until early 2006, which can let go without warning in high powered variants (supercharged). The flywheel bolts supposedly can shear (again, in high powered variants).
 

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You got the Ski for a great price, find out how much the Bolts and valves cost, if reasonable then replace them and you can put a slightly higher boost impeller in the Super charger.
They have blades that can give more boost lower down or higher up, depends what you want to do with the Ski, Speed or towing or both.

I got my Ski for a little over $3000 less than they were selling for with low hours and so I spent $3000 doing some improvements and mods.
All that I did improved fuel economy and handling as well as engine reliability.
I also now get 68mph with two people and haven't changed the revs of the engine.
I can get a tune and boost revs to 8K or 8.5K and get a huge boost to top speed.

I mainly wanted reliability and if the things I did also improved economy and performance then a bonus.

Also what you need to look at is, how much would you have spent on a good reliable Ski and how much would it cost to replace bolts or Valves if they do let go ?
It's normally cheaper to do it before anything breaks :)
Well it has been for me as a Valve bouncing around inside a cylinder normally doesn't improve the piston to much and if the bolts on a flywheel shear, I can only imagine how much good it would do spinning at 7K as it lets go as I am sure it wouldn't shear at low revs ?
Probably as you jump a wake or wave and land with the revs high as you forgot to decelerate as you launched or started to accelerate before you hit the water ?
They are easy enough to work on and if you enjoy working on Engines and such as I do then it's also fun :)
Hope you get a ton of fun from your Ski :)
 
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