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What fuel for the RFI?

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NX EXA

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Nosing a bit in the 2002 operator's guide and I'm going through the specs on the different models seeing what's different about them. The one's listed are: GS, GTI, GTI LE, GTX, GTX RFI, XP, RX, RX DI.

Looking at the power output, the GTX RFI and the RX DI have the same (and the highest) at 270 W @ 6000 RPM. I don't know what the conversion is. Anyway, all the doos list 87 octane except for the RX DI at 91 octane. With the RFI running the same power, should I also be running 91 octane?

What's your take?
 
Use the reg octane. Most skis are designed to run the 87 octane from factory. Some people like to run the 91 for less/no ethanol. As long as you have stock compression, you can run the 87. Any mods to compression domes/racing heads then I would go up to 91, even higher to avoid pre-detonation.

Start off with the 87. But if you notice a "pinging" sound in your engine at mid-high throttle, go up to higher octane. Find what your ski likes and stick with it.
 
Exactly, and older fuel tends to loose octane as well. Higher compression makes an engine more sensitive to octane, leaner air:fuel ratios, and higher oil ratios also reduce effective octane.

So it's not a bad idea to keep octane in mind, and look/listen for signs of pre-ignition and detonation which when they happen (often on carbed engines running too lean) are known to eat piston crowns. Watch your plugs and piston crown, you can get a good idea of how things are going by using a bore scope, or even removing the RAVE valves to monitor your piston crown and just by the feel and sound of the engine, if it feels flat and unresponsive to the throttle or loses RPM when running at speed with a constant throttle position there could an issue.

I've tried higher octane fuel in my 951 carb motor out of curiosity, and haven't noticed any differences(improvements) in how it runs or sounds.
 
For my own curiosity, I'm wondering what your piston crowns, piston skirts around ring lands, and RAVE valves look like if you've already inspected them by chance.

The few pics I've seen of the 951 DI's looked remarkably clean to me, with what looked like maybe some varnish around the ring lands on one that was burning TC-W3(the wrong oil).
 
Okay, remember I'm a complete newb to these watercrafts. Can I tell all this just by removing something simple? Please inform as I'm curious myself since it it's currently running the wrong oil. I will look into it this weekend.
 
Okay, remember I'm a complete newb to these watercrafts. Can I tell all this just by removing something simple? Please inform as I'm curious myself since it it's currently running the wrong oil. I will look into it this weekend.

No, I'm not advocating you should rip your ski apart, I'm a firm believer any neub should fly low and slow instead of ripping and tearing. Your ski may be in need of some service at some point though, I'm glad to see you're doing your due diligence in advance.

If you don't have the BRP shop manual and you intend on working on your ski (even simple maintenance, which is probably all you'll need since it's running well), then you should get your hands on one. Of course just b/c you have the shop manual, that doesn't give you automatic license to reman the motor, but it's a valuable reference source for when you need to perform maintenance.

Could be, your ski was well maintained, and just recently well serviced in the last 6 months or something, in which case you're making preparations.

A few thing's you're probably contemplating:

Pump oil change
RAVE valve cleaning
Switch to correct oil
Compression test ("fingerprinted" for future reference, good to have)
Grease PTO spline
How to clear water if ski happens to sink

I was just curious if you'd recently looked at your combustion chambers, don't rip into it on my account, do it when you're prepared, if/when you intend on doing it. Also, if you ever tear your engine down, I'd like to know how much oil you find lying in the bottom of the crankcase, there should be a puddle of it there. I'm dang not going to tear mine apart just to find out, I guess you won't either, hopefully!

I do plan on performing some or all of the above items before/during winterizing my boat within the next few months, I like doing one thing at a time and then test the boat to make sure I didn't mess something up, doing too much in one shot can result in complication and confusion.
 
Yes, the previous owner took very good care of it. She said she hasn't had to do a thing to it other than regular maintenance. I won't be digging into the doo until there is a problem. I am wanting to switch to the correct oil. Don't know if the pump ol is correct or not, nor how to change it. ... or the engine oil for that matter. I don't know what all gets greased and lubed on a regular maintenance basis. There's a lot I need to learn of these machines. I can do cars, jet pumps are all new to me.
 
I use 91 for everything i own. Used to use 93 but they stopped making it. Now a few stations sell it but crazy expensive
 
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