Gas Octane Rating & Tuning/Setting up Carbs...

[nitr0genics]

Just a quick one, had the carbs out the 787 for a overhaul etc and setting everything to spec as per the manual and got to thinking.. the RON of the fuel over there (in the US) is lower than it is here (in the UK) I think, if the tech sheets are anything to go by anyway, spec shows minimum octane rating to be 87 which I guess is your standard gas at the pump? However over here, our minimum at the pump is 95 RON with "super" available at 98 RON

Also is the min rating in the manual in RON or AKI? think you US guys use AKI instead of RON which if memory serves is about 4-6 octane down on the RON figure, so 87 rating would actually be about 92/93 RON

So would I be right in the thinking running a higher octane fuel would require slightly different from spec parameters or is it just negligible?

 

[mikidymac]

The fuel rating on a stock ski has nothing to do with the carb settings. Seadoo calls for the same "regular" fuel as the auto industry so whatever your standard fuel is should be fine. I run "super" 91 octane in mine just because we have crap fuel here in California and it degrades quickly.

 

[Sportster-2001-951C-Stock]

As long as your fuel is fresh, there's no hesitation or air leaks, and the plug insulator steady-state color settles to cardboard brown then you should be good, I expect there's slim chance the factory tune will be too rich.

I burn 87 rated in my (rejetted-fatter, original carbs) 951 with no additives or preservatives of any kind and no issues but I make sure it's fresh (less than 3 months old). Next time I'll install nylon fuel lines, most likely.

Our current fuel is so highly cracked and whipped then blended with what must be mink milk, it only smells slightly like gasoline should for a few months before it begins to take on a dead skunk odor and cannot even be used to ignite a dry brush pile due to it just goes poof !